Hundreds of Palestine supporters have marched through Sydney in protest against the Opera House being lit up in blue and white in support of Israel following attacks by militant group Hamas.

The conflict has so far killed at least 700 people in Israel, including 260 at a music festival, and seen around 130 people taken hostage.

Israel has responded by launching a devastating barrage on the Gaza Strip, killing at least 560 Palestinians, including dozens of children.

READ MORE: A 'Pearl Harbour' moment: Why didn't Israel's sophisticated border stop attack?

Israel on Monday vowed a complete siege of the region, having already cut power to the densely populated enclave, making it increasingly difficult for health workers to treat the more than 2200 injured people in Gaza.

About 6pm on Monday, hundreds of people began gathering outside Sydney Town Hall before moving through the CBD towards the Opera House.

People carried Palestinian flags, wearing black, white, red and green, and carrying banners with messages such as "Apartheid, wrong in South Africa, wrong in Palestine" and "Free Palestine".

"Resistance is justified as long as more than 2 million Palestinians in Gaza are forced to live in an open air prison for the past 15 years," one speaker with family in Gaza said, condemning "massacres, pogroms, land confiscation".

"As long as Palestinians in Jerusalem and the surrounding cities are being ethnically cleansed and forced to live under the boots of the Zionist fascist occupation day in and day out for the past 75 years."

The Nakba, or catastrophe, refers to the mass displacement of Palestinians during the 1948 Arab-Israeli war.

One of the march's organisers, Josh Lee, said lighting the Opera House in an expression of support for Israel was "disgusting", given the Palestinians were oppressed victims.

Prime Minister Anthony Albanese had earlier called for the march to be called off out of respect for the loss of life in Israel since Saturday.

"The actions of Hamas in this is completely indefensible," Albanese told 2GB radio this afternoon, adding that "this was people killing innocent civilians".

Greens state MP for Newtown Jenny Leong criticised the prime minister's comments and the lighting of the Opera House "in support of those bombing Palestinian people in Gaza into oblivion".

"Disgraceful to see political leaders fail to recognise the complexity and reality of this human rights and humanitarian crisis," she said.

There was a heavy police presence keeping an eye on the march, with both mounted officers and some on foot.

EXPLAINED: What you need to know about the Hamas attack on Israel

The group organising the march, Palestine Action Group Sydney, said it would be a "mass, peaceful protest" and police also described the event as "peaceful".

A man who attended the march with an Israeli flag was arrested and removed "to prevent a breach of the peace", police said.

He was issued with a move-on order and wasn't facing any further action.

Video footage posted to X shows the man, with his flag in a tennis bag after he had waved it earlier, exchanging words with some members of the pro-Palestinian crowd near Town Hall before walking away without further incident.

Some estimates put crowd numbers at about 1000.

Sydney's Jewish community said police had warned them to stay away from the Opera House while it was lit up.

"NSW Police and Community Security Group (CSG) are urging the community not to attend the Sydney Opera House precinct or Town Hall this evening," the NSW Jewish Board of Deputies said in a statement.

"Community members already in the CBD should also be vigilant as protesters are likely to seek to march from Town Hall to the Sydney Opera House.

READ MORE: Family plea after video shows unconscious woman in Hamas' hands

"The events tonight may pose a risk to the safety of community members and you are strongly urged not to attend.

"NSW Police and the CSG have confirmed unequivocally that it is safe to continue to participate in all official Jewish communal events and to send your children to school in the usual way."

The Opera House was one of several Australian landmarks, including Parliament House in Canberra and the Adelaide Oval, to be lit up in blue and white on Monday in support of Israel.

In Melbourne, Deputy Prime Minister Richard Marles attended a Jewish community gathering where he said Australia's "heart breaks for Israel" .

"We do condemn Hamas in the strongest possible terms. Theirs is an ideology of terror and these are acts which are of the most profound evil," he said.

"And as Israel acts to defend herself, and to seek the protection and the liberation of her citizens to act against Hamas, Australia stands by her side.

"And in 2023, it is time around the world that there is an acknowledgement that Israel has the right to exist in peace and in security."

Israel-Hamas war: What we know so far

• Hamas militants crossed into Israel by land, sea and air in the early hours of Saturday morning. The militants infiltrated 22 towns and army bases. Civilians and soldiers were killed and taken hostage.
• At least 700 people have reportedly been killed in Israel.
• Israel formally declared war on Hamas on Sunday and has been pounding Gaza with airstrikes.
• More than 550 Palestinians have reportedly died. Hamas has fired over 4000 rockets into Israel.
• The Wall Street Journal today reported Iran helped Palestinian militants plan their shock assault. Iran has denied it was involved in the attack, but has supported it as "wholly legitimate". A US official said it had no "direct information" linking Iran to the attacks.

LIVE UPDATES: Hundreds of people are marching in protest against Australian landmarks, including the Sydney Opera house, being lit up in support of Israel.

Jim Bolger was the first PM who had to strike a deal with Winston Peters under MMP.

Victorian Premier Jacinta Allan was warned about the Commonwealth Games cost blow-out four months before its cancellation, an inquiry has heard.

The evidence was given on the first day of public hearings at a state upper house inquiry into Victoria's shock decision to axe the games.

Department of Jobs, Skills, Industry and Regions secretary Tim Ada told the inquiry that the event's costs had nearly doubled from $2.6 billion in March 2022 to $4.5 billion a year later.

READ MORE: Lawyers hired weeks before cancellation of Commonwealth Games, documents show

Ada found the business case did not "reflect the true cost of delivering a sporting program spread across five cities".

He said the case relied on "top-down estimates and benchmarking against known amounts from the 2018 Gold Coast Games".

Ada said in early March, the department briefed Allan on the "revised budget requirements to deliver the Games".

"An updated budget estimate of $4.5 billion was not approved, with the department asked to further explore opportunities to reduce costs while still meeting the government's commitment to host the Games in regional Victoria."

Between April and June, the government worked to put together a new budget, however, it became clear there were risks emerging as planning progressed, Ada said.

He said another revised budget submission of $4.2 billion was made by the department but it had not been approved.

READ MORE: Dozens of tobacco stores targeted as illicit trade war escalates in Melbourne

Former Premier Daniel Andrews made the shock announcement to cancel the games four days later, on July 18.

The cost of cancelling the games will cost taxpayers $380 million, after the government reached a settlement with the federation.

The inquiry also heard from Commonwealth Games chief executive Jeroen Weimar, who revealed he was still on the payroll.

"The vast majority of our staff have been made redundant, there are a handful of us left as we do the final closeout," he said.

He said the organising committee became concerned about the cost blowout.

"Through our work, it became clear by the middle of February it would not be enough."

"We had very little room for planning and for consultation and for contingency."

While Weimar knew costs were rising, the inquiry heard the state's top public servant Jeremi Moule uncovered the cost blowout.

"It was the advice of my department provided by me personally to the Premier that gave the government cause to reconsider the delivery of the Games," he said.

The inquiry will formally "request the attendance of Premier Allan" at a public hearing.

Allan has maintained she will not be appearing before the inquiry. 

Committee Chairman David Limbrick said the government needed to be held accountable and said "a lot of questions" needed answers.

"I hope the Premier will consider the invitation," he said.

The public hearings continue, while an interim report is due to be handed to parliament by the end of April 2024.

His website included a reference to Dr Raj being a third-generation doctor.

The US Powerball jackpot swelled to an estimated $US1.55 billion ($2.4 billion) for Monday night's drawing after weeks with no grand prize winner.

The new mammoth prize up for grabs ranks as the third-largest Powerball jackpot and fourth-largest among US lottery jackpots, according to Powerball's website.

If a player matches all six numbers to win the jackpot, they will have the choice between an annuitised prize worth an estimated $US1.55 billion ($2.4 billion) or a lump sum payment estimated at $US679.8 million ($1.06 billion) – both before taxes, Powerball said.

READ MORE: The one huge question about Israel attack that needs answering

The grand prize grew on Saturday after no ticket matched all six numbers drawn, 47, 54, 57, 60, 65 and red Powerball 19.

There have been no Powerball jackpot winners since July 19, when a single ticket sold in California nabbed a grand prize worth $US1.08 billion ($1.69 billion).

The upcoming drawing will be the 35th in this jackpot run. It's the first time in Powerball's history that back-to-back cycles have generated billion-dollar grand prizes, Powerball said in a news release.

While no one scored the jackpot during the last drawing Saturday, there were still some big wins.

READ MORE: What we know about the people captured by Hamas

Ten tickets matched five numbers to win $US1 million ($1.5 million) prizes in California, Kansas, Louisiana, Massachusetts, Michigan, Ohio, Texas and Wisconsin.

Another two tickets, sold in Iowa and Maine, matched all five white balls and won $US2 million ($3.1 million) each because their holders activated a "power play" multiplier, Powerball said.

Overall, the odds of winning a prize are 1 in 24.9.

But the odds of winning the jackpot are much slimmer, at 1 in 292.2 million, Powerball says.

The largest Powerball Jackpot ever won was a $US2.04 billion ($3.2 billion) prize from November 2022, followed by a $US1.586 billion ($2.4 billion) jackpot won in January 2016.

All figures in this story are in Australian dollars.

There are many different ways to get help and information about gambling. Call the National Gambling Helpline on 1800 858 858; use online counselling; find information about help services in your state or territory; get information and support for family and friends; get information about how to talk with someone about their gambling; or contact Gamblers Anonymous. All services are free, confidential and available 24 hours a day, 7 days a week.

The gunmen came from air, sea and land. They shot at civilians, took hostages and forced families to barricade themselves indoors, fearing for their lives.

A day that began with air raid sirens blaring out in the early morning had by lunchtime turned into one of the most terrifying attacks Israel has known in the 75 years of its existence. Assailants from Hamas, the Islamist militant group that controls the impoverished and densely populated Gaza Strip, had by nightfall killed hundreds of people and wounded hundreds more.

READ MORE: 5 things to know about the Hamas attack on Israel

Though Israel is no stranger to terrorist attacks, Saturday's assault was unprecedented – not least because of the lack of warning. Israel's military on Saturday found itself caught off-guard, despite decades in which the country became a technology powerhouse that boasts one of the world's most impressive armed forces and a premier intelligence agency.

The questions for Israeli authorities are legion. It has been more than 17 years since an Israeli soldier was taken as a prisoner of war in an assault on Israeli territory. And Israel has not seen this kind of infiltration of military bases, towns and kibbutzim since town-by-town fighting in the 1948 war of independence. How could a terror group from one of the world's poorest enclaves manage to launch such a devastating attack?

"The entire system failed. It's not just one component. It's the entire defence architecture that evidently failed to provide the necessary defence for Israeli civilians," said Jonathan Conricus, a former international spokesman for the Israel Defence Forces.

"This is a Pearl Harbour-type of moment for Israel, where there was reality up until today, and then there will be reality after today."

READ MORE: Music festival goers heard rockets, then Gaza militants fired on them

The IDF has repeatedly dodged questions about whether Saturday's events constitute an intelligence failure. Military spokesman Lt. Col. Richard Hecht told CNN that Israel was focused on the current fight and protecting civilian lives.

"We'll talk about what happened intelligence-wise after," Hecht said.

'Obviously not adequately protected'

Whether by coincidence or design, the attacks came the day after the 50-year anniversary of another unforeseen conflict, when a coalition of Arab states launched a surprise attack against Israel on Yom Kippur, the holiest day of the Jewish calendar, in 1973.

Since Israel withdrew from Gaza in 2005, it has spent billions of dollars securing the border from attacks. That has striking at any weapons fired from inside Gaza into Israel and stopping terrorists from trying to cross the border from air or underground using tunnels. To stop rocket attacks, Israel has used the Iron Dome, an effective rocket defense system developed with help from the United States.

Israel also spent hundreds of millions of dollars building a smart border system with sensors and subterranean walls that was, according to Reuters, completed at the end of 2021.

READ MORE: Hamas captures hostages as Israelis share photos of those missing

Israeli officials will almost certainly look at where those systems failed on Saturday. As of Saturday morning, Israel said Hamas had fired 2,200 rockets, though it did not release figures on how many of those were intercepted. Officials have not commented on if the border fence did its job.

Aaron David Miller, a former State Department negotiator on Middle East issues, told CNN's Wolf Blitzer that Israeli communities near Gaza were "obviously not adequately protected."

"I just don't think the Israelis saw this coming," Miller said.

How Israel responds will likely involve more than just border reinforcements. The Israel Defence Forces have already begun airstrikes in Gaza targeting Hamas infrastructure, resulting in hundreds of dead and injured.

Israeli Prime Minister Benjamin Netanyahu said that the country will "return fire of a magnitude that the enemy has not known", while the top official in charge of activities in the Palestinian territories, Maj. Gen. Ghassan Alian, said that Hamas had "opened the gates of hell."

Conricus, the former IDF spokesman, said Saturday's events will force Israel to back up that rhetoric and respond "in a way that it has never responded before."

Analysis by Joshua Berlinger

The young man was “always so kind, friendly, and always happy to help”, tributes say.

Victim’s father: ‘My son will bear the scars for the rest of his life.’

A father and son have been identified as the victims of a fatal plane crash north of Adelaide.

Pilot Ben Mumford, 50, and his son Charlie Mumford, 24, were inside a light aircraft when it hit power lines and crashed at Redhill near Crystal Brook, two hours north of Adelaide yesterday.

The plane burst into flames on the ground, sparking a grass fire which was put out by CFS.

READ MORE: The one huge question about Israel attack that needs answering

It's understood another of Ben's sons, Lachlan Mumford, was one of the first on the scene.

He helped rescue his father and brother from the wreckage, before being taken to hospital with burns of his own.

The 50-year-old pilot died shortly after he was flown to Royal Adelaide Hospital, while his son died at the scene.

EXPLAINED: What you need to know about the Hamas attack on Israel

Michael Hammill said the community had been rocked by the deaths.

"They were just a wonderful family," he said.

"Ben was the first one to come and see you and make sure you're alright."

Major crash officers spent the day combing the scene.

Investigators from the Australian Transport Safety Bureau are also on the scene.