REUTERS- At least eight people have been killed and many more wounded after one or more gunmen opened fire in a school in the Russian city of Kazan, the RIA news agency reported on Tuesday, citing the emergency services ministry.

Two children could be seen leaping from the third floor of the four-storey School Number 175 as gunshots sounded, in a video filmed by an onlooker that was circulated by RIA.

Some Russian news agencies reporting two teenage gunmen were involved and others said a sole shooter took part.

RIA said one 19-year-old gunman had been detained and that an explosion had been heard at the school. Footage posted on social media showed a young man being pinned to the ground outside the school building by a police officer.

Footage also showed emergency service vehicles parked outside the school, with people running towards the building.

It was not clear whether any other shooters remained at large. Nor was it immediately clear what the motive for the attack was.

School shootings are rare in Russia. One of the last major shootings of its kind took place in Russian-annexed Crimea in 2018 when a student at a college killed 19 before turning his gun on himself.

Kazan is the capital of the Muslim-majority region of Tatarstan and located around 450 miles (725 km) east of Moscow.

A teenager was detained after the attack at the school, located some 820km (510 miles) east of Moscow in the mainly Muslim republic of Tatarstan. Police have opened an investigation, but no motive has yet been established.

Tatarstan President Rustam Minnikhanov described the shooting as a “disaster” and a “tragedy”.

Heavily armed police and emergency vehicles responded to the shooting at School No. 175 on Tuesday.

Footage shared on social media showed some children jumping from windows to escape as well as injured people being evacuated.

Reports initially said that there were two shooters, one of whom had been killed. But officials later said there was only one suspect.

Mr Minnikhanov told reporters outside the school that in addition to the fatalities, 12 children and four adults were being treated in hospital.

“The terrorist has been arrested. He’s 19. He’s a registered firearm owner,” he said.

One video on social media captured a teenager lying on the ground apparently being detained outside the building.