At least nine fatalities were reported on Tuesday when a gunman attacked a school in Kazan, southwestern Russia. According to regional governor Rustam Minnikhanov, seven of the dead were eighth-grade students at the school, while the killer is a 19-year-old “terrorist” who is now in custody.

“The terrorist has been arrested, 19 years old. A firearm is registered in his name. Other accomplices haven’t been established. An investigation is underway,” Minnikhanov said after visiting School Number 175 in Kazan, the capital city of the Muslim-majority republic of Tatarstan.

Minnikhanov described the attack as a “great tragedy” and said the dead included four boys and three girls who attended the school, plus a teacher and a female staffer. He said 18 children and three adults were injured in the morning attack. Some local officials put the number of fatalities as high as 11 and said six children remain in intensive care.

The Russian Interior Ministry released a brief statement on the event that also suggested “terrorist” activity:

This morning Tatarstan police received a message that in School 175 in Kazan the sound of shots were heard. According to preliminary information, there are dead and wounded.

Police and other law enforcement officers immediately went to the scene. The attacker was detained by officers of the patrol service. The law enforcement operation is still ongoing at the school. Every effort is being made to ensure the safety of the students. A counter-terror regime has been implemented.

Both Minnikhanov and Russian national officials described the assailant as a “registered gun owner.” Russian parliamentarian Alexander Khinshtein wrote on social media the attacker was issued a permit for a Hatsan Escort PS shotgun.

Russian President Vladimir Putin’s spokesman Dmitry Peskov suggested Russia’s gun laws could be revised in the aftermath of the shooting.

“The fact is that sometimes types of small arms are registered as hunting weapons, which in some countries are used as assault rifles, and so on. This will also be urgently worked out by the Russian Guard,” Peskov said.

Peskov said doctors, medical equipment, and psychologists have been sent to Kazan by the central government, along with the ministers of health and education.

As is often the case with such events, rumors swirled about accomplices and second shooters, but Tatarstan officials said late on Tuesday morning they believe there is only a single suspect, although other schools in the area were put on alert as a precaution. The shooter in custody was named by local media as Ilnaz Galyaviev, a resident of Kazan and possibly a graduate of School Number 175.

“The suspect went on social media before the attack, posting that he planned to kill a ‘huge number’ of people before shooting himself. Screenshots of his account, now blocked, show him wearing a black mask with the word ‘god’ written across it in red,” the BBC reported.

Video posted to social media showed children climbing out of windows to flee the school and a heavily-armed squad of Russian FSB troops gaining entry. Some eyewitnesses reported hearing an explosion before the gunfire began. Russia’s Tass news service quoted education ministry officials who said the suspect told them he planted a bomb at the school’s registration desk.