Seven children and a teacher have been killed in a shooting at a school in the Russian city of Kazan, officials say.

More than 20 others, mostly children, were reportedly wounded. A 19-year-old suspect was detained.

The attack happened 820km (510 miles) east of Moscow, in the mainly Muslim republic of Tatarstan.

Prime Minister Mikhail Mishustin spoke of "great sorrow", while Tatarstan's leader Rustam Minnikhanov described the attack as a "major tragedy".

"We are deeply saddened that this has happened," he said.

Responding to the shooting, Russian President Vladimir Putin said he would review the country's gun control laws.

The shooting happened at School No. 175 early on Tuesday.

A source in the emergency services told Russian news agency Tass that the attack began at about 09:20 (06:20 GMT), with the first signal from a panic button at the school five minutes later. Heavily armed police and emergency vehicles responded to the incident.

The suspected attacker has been widely named locally as Ilnaz Galyaviev. Russian investigators said he was a Kazan resident thought to have studied at the school in the past.

Footage shared on social media showed some children jumping from windows to escape as well as injured people being evacuated. Russian TV reported that two of the children died after jumping from a second-floor window.

"Everyone started panicking and saying 'shut the doors'," a student who witnessed the attack told the Mediazona news website. "About a minute later the head teacher started yelling: 'We're shutting the doors!'

"We got out about 15 minutes later, not out of the windows. I wanted to do that, but the teacher closed the window immediately and said no," he said.

Reports initially said that there were two gunmen and that one of them had been killed. But officials later said there was only one suspect.

Officials have confirmed eight deaths. Mr Minnikhanov said the victims included four male and three female eighth-grade students. His press service later added that a teacher was also killed.

More than 20 others were injured, according to local media reports.

Mr Minnikhanov said 12 children and four adults were being treated in hospital. Six children are said to be in a critical condition.

"The terrorist has been arrested. He's 19. He's a registered firearm owner," he said.

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

After the attack Kremlin spokesman Dmitry Peskov said President Putin had ordered the chief of Russia's National Guard to "work out as a matter of urgency new regulations on the types of weapon that can be in civilian circulation and that can be owned by the public".

The instruction was issued "given the type of firearm used by the shooter", Mr Peskov said. "The fact is that sometimes types of small arms are registered as hunting weapons, which in some countries are used as assault rifles," he explained.

A Kazan resident outside the school told Moscow Echo radio station that people there were "hysterical". "Parents are crying, medics are giving out medicine," she said.

Authorities have called for all schools in Tartarstan to be inspected and have their security stepped up.

A day of mourning will be held on Wednesday to honour the victims. (BBC)

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