An Indonesian passenger aircraft carrying 11 people has gone missing just before it was scheduled to land yesterday, while approaching a mountainous region in Sulawesi.

The turboprop ATR 42-500 operated by the Indonesia Air Transport was on its way from Yogyakarta to the capital city of South Sulawesi when it vanished from radar, Endah Purnama Sari, a spokesperson for the Transportation Ministry, said.

The plane was last tracked at 1.17pm (4.17pm AEDT) in the Leang-Leang area of Maros, a mountainous district of South Sulawesi province.

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Multiple search and rescue teams, supported by air force helicopters, drones and ground units have been deployed, Sari said in a statement.

Hopes for locating the wreckage grew after hikers on Mount Bulusaraung reported finding scattered debris, a logo consistent with Indonesia Air Transport markings, and small fires still burning at the scene.

“The sightings were reported to authorities and are being verified by rescue teams attempting to reach the area,” said Major General Bangun Nawoko, the South Sulawesi’s Hasanuddin military commander.

Sari said the plane disappeared shortly after being instructed by air traffic control to correct its approach alignment.

“After the last ATC instructions, radio contact was lost and controllers declared the emergency distress phase.”

She said rescue teams focused their search on the mountains where the aircraft, with eight crew members and three passengers from the Marine Affairs and Fisheries Ministry aboard, was believed to have deviated from its approach to Sultan Hasanuddin International Airport.

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Weather conditions at the time indicated clouds and eight-kilometre visibility, Sari said.

Steep terrain at Bulusaraung National Park linking Maros and Pangkep districts complicated the search efforts, Nawoko said.

Minister of Marine Affairs and Fisheries Sakti Wahyu Trenggono told a news conference late Saturday that three employees of his ministry were aboard the flight as part of an airborne maritime surveillance mission supporting Indonesia’s fisheries management operations.

Indonesia, the world’s largest archipelago nation with more than 280 million people, relies heavily on air transport and ferries to connect its over 17,000 islands.

The Southeast Asian country has been plagued by transportation accidents on land, sea and air in recent years because of poorly enforced safety standards.

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Iran’s Supreme Leader Ayatollah Ali Khamenei branded US President Donald Trump a “criminal” for supporting protesters in Iran, and blamed demonstrators for causing thousands of deaths.

In a speech broadcast by state television, Khamenei said the protests had left “several thousand” people dead — the first indication from an Iranian leader of the extent of the casualties from the wave of protests that began on December 28 and led to a bloody crackdown.

“In this revolt, the US president made remarks in person, encouraged seditious people to go ahead and said: ‘We do support you, we do support you militarily'," Khamenei, who has final say on all state matters, said.

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He reiterated an accusation that the United States seeks domination over Iran’s economic and political resources.

“We do consider the US president a criminal, because of casualties and damages, because of accusations against the Iranian nation,” he said.

He described the protesters as “foot soldiers” of the US and said they had destroyed mosques and educational centres.

“Through hurting people, they killed several thousand of them,” he said.

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In response, Trump called for an end to Khamenei’s nearly 40-year reign.

“The man is a sick man who should run his country properly and stop killing people,” Trump told Politico in an interview on Saturday (Sunday morning AEDT).

“His country is the worst place to live anywhere in the world because of poor leadership.”

“It’s time to look for new leadership in Iran," he added.

Trump had sounded a conciliatory tone

The back-and-forth rhetoric came a day after Trump sounded a conciliatory tone, saying “Iran cancelled the hanging of over 800 people” and adding “I greatly respect the fact that they cancelled”.

He did not clarify whom he spoke to in Iran to confirm the state of any planned executions. His comments were a sign he may be backing away from a military strike.

The official IRNA news agency reported that Tehran Prosecutor General Ali Salehi, referring to Trump's remarks about the cancellation of the death sentence of 800 protesters, said: “Trump always makes futile and irrelevant statements. Our attitude is severe, preventive and fast.”

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He did not elaborate.

In recent days, Trump had told protesting Iranians that “help is on the way” and that his administration would “act accordingly” if the killing of demonstrators continued or if Iranian authorities executed detained protesters.

In his speech, Khamenei said rioters were armed with live ammunition that was imported from abroad, without naming any countries.

“We do not plan, we do not take the country toward war. But we do not release domestic offenders, worse than domestic offenders; there are international offenders. We do not let them alone either,” he said, and urged officials to pursue the cases," he said.

An uneasy calm

Iran has returned to an uneasy calm after harsh repression of protests that began December 28 over Iran’s ailing economy.

The crackdown has left at least 3095 people dead, according to the US-based Human Rights Activists News Agency, exceeding that of any other round of protest or unrest in Iran in decades and recalling the chaos surrounding the 1979 revolution.

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The agency has been accurate throughout the years of demonstrations, relying on a network of activists inside Iran that confirms all reported fatalities. The AP has been unable to independently confirm the toll.

Iranian officials have repeatedly accused the US and Israel of fomenting unrest in the country.

On Friday, Iran’s President Masoud Pezeshkian, in a phone conversation with Russian President Vladimir Putin, accused the US and Israel of meddling in the unrest.

Reports of limited internet access briefly restored

There have been no signs of protests for days in Tehran, where shopping and street life have returned to normal, and Iranian state media have not reported any new unrest.

During the protests, authorities blocked all internet access on January 8. On Saturday, text messaging and very limited internet services began functioning again briefly in parts of Iran, witnesses said.

Cellphone text messaging began operating overnight, while users were able to access local websites through a domestic internet service. Some also reported limited access to international internet services via the use of a virtual private network, or VPN.

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The extent of access and what was behind it wasn’t immediately clear. It's possible that officials were turning on some systems for the start of the Iranian working week, as the outage has affected businesses, particularly banks in the country, trying to handle transactions.

Internet traffic monitoring service Cloudflare and internet access advocacy group NetBlocks reported very slight increases in connectivity on Saturday morning, while Iran’s semi-official Mehr news agency also reported limited internet access. It did not offer an explanation.

No new protests reported after exiled Iranian royal's call for further demonstrations

A call by Iran’s exiled Crown Prince Reza Pahlavi for protesters to take to the streets again from Saturday to Monday did not appear to have been heeded by Saturday afternoon.

Pahlavi, whose father was overthrown by Iran’s 1979 Islamic Revolution, enjoys support from die-hard monarchists in the diaspora but has struggled to gain wider appeal within Iran.

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However, that has not stopped him from presenting himself as the transitional leader of Iran if the government were to fall.

There were protests in London overnight outside the Iranian embassy, with one man trying to steal the flag from the front.

Police arrested 14 people for disorder, with some being injured.

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Judge: ‘I have to plant you somewhere where you will be safe, where you will be loved.’

Climate change could be driving the emergence of sinkholes across Australia, experts say.

Several sinkholes have cracked wide open in multiple states in recent months – including a massive hole on a football field in Melbourne's north-west and a crater in the middle of the street in Adelaide's inner-south.

There are both environmental and man-made reasons for these suburban sinkholes.

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But increased extreme weather events could make them far more prevalent.

Sinkholes mostly occur in areas underlain by limestone or carbonate rocks, which can concave due to chemical weathering, Melbourne University's Infrastructure Engineering Associate Professor Shiao Huey Chow told nine.com.au.

Water is one of the root causes, which erodes bedrock over time and creates caverns.

"The main environmental agents for the chemical weathering are water and temperature," Chow explained.

"Therefore, in areas where you can find limestone, any increase in temperature or changes in rainfall patterns due to climate change can accelerate the dissolution and introduce higher sinkhole risk."

Research has found there is evidence linking sinkholes to climate change, including droughts and floods.

Heavy rainfall and surface flooding can trigger the collapse of normally stable cavities and erode soil to form new "subterranean voids", according to a scientific journal published on Nature.com.

"Additionally, rising water tables – driven by increased rainfall and storm frequency – may further destabilise ground," the research states.

Heatwaves and drought can also contribute to sinkholes.

"It has been shown that sinkhole frequency in karst environments of north-east Spain increase[s] during drought," the journal notes.

Countries such as China and Iran have karstic landscapes, which are at high risk of sinkholes.

In China alone, there is around 600,000km² of ground which could collapse.

Some metropolitan areas in Australia may be under threat of sinkholes developing suddenly due to plumbing issues or movement weakening the ground above old mine shafts.

Business development manager at Rectify Group Phil Irwin said "people have no idea" of how many areas are at risk.

There could be countless undocumented mine shafts that authorities do not know about, he said.

"Sinkholes can develop anywhere, anytime," Irwin said.

"Some of the mine shafts are recorded, not all of them were, because you just had people digging holes left, right and centre.

"We've encountered them when we've been trying to treat people's properties."

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Irwin warned sinkholes can pop up in your backyard during construction work.

"If you've got a pipe that's cracked and a bit of soil falls into the pipe, it could bubble out and collapse," he said.

"We've had plenty of those in the past but they're easily rectified because they're typically not very deep.

"But it's when you've got something that's a little bit larger and it's involving infrastructure like roads, that's where it's a little bit more significant."

What are the early warning signs of a sinkhole?

There are a few signs that point to an eventual sinkhole.

This can include structural issues such as cracks in the walls and floor, or doors and windows that don't close properly.

On the ground, evidence of sinkholes can be buried items becoming visible, small ponds forming, depressions spots on the fround or slumping trees and fences.

How do you get rid of sinkholes?

Sinkholes are rectified using different methods depending on the size.

Irwin recommends resin injection, which involves stabilising the ground by injecting expanding polyurethane resin into the soil through small holes.

Bigger sinkholes, such as collapsed mine shafts, can usually be fixed by pumping cellular concrete into the cavity.

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Victoria's Great Ocean Road has reopened to traffic around the communities smashed by extreme flash flooding as residents and holidaymakers begin the huge clean up.

Melanie and Martin were arriving at their Separation Creek home when the water came screaming through on Thursday.

"We heard this cracking, roaring, cracking, and watched as our bed in our second bedroom just literally flew out under the bridge, fully made up, pillows, duvets out to sea," Melanie said.

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"Literally just watched this water torrenting down the creek and the land slipping away before our eyes."

The property once had rooms on both sides of the creek but it has been completely separated.  

The force of the water tore the bridge off its foundations and destroyed the area the couple had revegetated with thousands of native plants. 

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"It's almost surreal, like you're watching a movie, this thing torrenting down," Martin said.

"You could actually hear timber crashing, like absolutely thundering down, and it was just getting more and more intense."

Their neighbour Peter Jacobs has lived in the area for 36 years.

He and his wife were trying to save their chickens when they were forced to run for their lives.

"I looked up and there was a wall, a tsunami of trees, ferns, water, and just the noise was extraordinary, and I just looked in total dismay," he said.

"And I said, 'get out, we've got to get out'."

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The couple managed to leave and have since been left isolated without power and a huge clean-up ahead of them.

Jacobs is hoping the council will arrive soon to assist.

"I've never experienced anything like this," he said.

"We can recover, but we just need some help, I need some help."

A few kilometres away at Wye River the clean up began first thing this morning after water bulldozed its way through the town. 

A large group of Country Fire Authority volunteers arrived to help.

One of the biggest tasks was rescuing two stranded cars that had been washed away.

Crews used a winch and a four-wheel-drive to salvage what was left of a Mazda.

The Volkswagen, which was trapped at sea on a rock, was also moved with some heavy machinery.

Many residents in the town of Wye River put their hands up to help with the massive clean-up and brought their families along.

"We've been cleaning up the bridge at the park and there's been a lot of rubbish everywhere," one child said.

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Robert Irwin's return to Australia has been celebrated with a lookalike search in his home town.

Hundreds turned out as the Sunshine Coast community hosted a lookalike contest to find the wildlife warrior's unofficial doppelganger.

"To welcome Robert Irwin home after six months, we had a bit of fun," Visit Sunshine Coast chief executive Matt Stoeckel said.

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"If Bindi Irwin had been here, she would have done a double take."

Thirty contestants battled it out on Kings Beach at Caloundra for the coveted title and bragging rights.

Robert lookalikes of all shapes and sizes strutted their stuff on a beachside catwalk in front of 300 people.

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Lookalike hopefuls tried to win over the judges with a range of props including toy crocodiles, blond wigs and the iconic khakis.

Stoeckel said the stakes were high with strict criteria to claim the crown.

"You had to own the crikey with confidence, you had to have that Robert Irwin physique and really be able to entertain the crowd with a bit of dance moves and some croc wrestling," he said.

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Caloundra father Ben Marshall took out the coveted title.

His striking similarity helped him win $500 in cash but it was his dance moves that got him over the line.

"I was up all night practising, so yeah, I'm glad I took out the win," Marshall said.

The real Robert took to social media to describe the contest as "classic".

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The AI ‘Bush Legend’ account has more than 211,000 followers online.

Police and NZTA have refused permission for the Tamaki-led march over the Harbour Bridge.

Emergency services were also called to Kai Iwi Lakes, Northland, about an hour later.

Campers have had to be rescued, hundreds of others have called for help and a woman has died when a tree branch fell on a car as wild weather batters the NSW coast.

The woman was killed while driving on the Illawarra Highway at Macquarie Pass when the branch fell about 4pm today. A male passenger was also injured.

One of three rescued campers had hypothermia when police and the SES rescued them from Geehi in Kosciuszko National Park in the Snowy Mountains last night.

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Across the state, SES volunteers have responded to hundreds of weather-related jobs, particularly in the South Coast, Illawarra, Sydney and Hunter regions over the last 48 hours.

Volunteers helped several people trapped in their cars as flash flooding hit Albion Park, Picton and Marulan in the Southern Highlands in the past 24 hours.

NSW SES Superintendent Matt Kirby reminded people to put safety first.

"This weather can produce heavy rainfall and strong winds, so we remind people not to drive through floodwaters and be wary of where you park your vehicles as tree branches can fall at any time," Kirby said.

"Download the Hazards Near Me app to stay up to date with any warnings that have been issued."

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Heavy rain has already drenched parts of the state over the last two days, in the worst storm of the summer.

In Moruya, almost 200 millimetres of rain fell in the 48 hours to 9am today.

It was warned that the slow-moving pressure system could bring up to 120 millimetres of rain in some parts of the NSW coast over 24 hours.

Heavy rain and damaging winds were likely to continue in Sydney, the Blue Mountains, the Illawarra and Shoalhaven.

Severe thunderstorms were also likely across the Central Coast and Mid North Coast regions.

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