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 and Prime Minister Mikhail Mishustin spoke of “great sorrow”.
The leader of Tatarstan said the attack was a “major tragedy” for the mainly Muslim republic.
“We are deeply saddened that this has happened,” said Rustam Minnikhanov.
Responding to the shooting, Russian President Vladimir Putin said he would review the country’s gun control laws.
School shootings are relatively rare in Russia. One of the last major incidents happened in Russian-annexed Crimea in 2018.
What do we know about the shooting?
The shooting happened at School No. 175 on Tuesday. Heavily armed police and emergency vehicles responded to the incident.
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.
A student who witnessed the attack described what happened to Russian news website Mediazona.
“Everyone started panicking and saying ‘shut the doors’. 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.
He told reporters outside the school that, in addition to the fatalities, 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.
The gunman has not been officially named.
What has the reaction been?
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.