MOSCOW (AP) — Russian President Vladimir Putin on Thursday said that the deadly school shooting in Kazan “has shaken” the country and ordered the government to revise school security protocols and tighten control over civilian gun ownership.

“The tragedy has definitely shaken all of us,” Putin said, speaking at a meeting with government officials via video link Thursday. “All of Russia... stands with Tatarstan, with Kazan residents, in the difficult days.”

A gunman on Tuesday morning attacked a school in Kazan, a city 430 miles (700 kilometers) east of Moscow, sending students hiding under their desks or running out of the building. Nine people — seven students and two school employees — were killed, and more than 20 others were hospitalized with injuries.

Three wounded children remain in grave condition, Health Minister Mikhail Murashko told Putin at the government meeting Thursday.

The authorities gave no motive as to why Ilnaz Galyaviyev, 19, who was arrested in the shooting, carried out the attack at the school he reportedly used to attend. He appeared in court Wednesday, charged with murder, and was ordered to pre-trial detention for two months. Officials said he legally owned a firearm.

Putin said Thursday that in order to prevent attacks like the one in Kazan, the authorities need to “seriously raise the requirements for civilian gun owners and tighten control over civilian gun circulation.”

“Decisions here need to be well-founded, and definitely tough,” the Russian president said, adding that officials granting gun ownership permits need to be held accountable for their actions.

Putin ordered the head of Russia's National Guard to put together a proposal on how to change gun ownership regulations.

The president also said that the tragedy in Kazan highlighted problems with school security, and tasked the government with introducing a unified security and anti-terror protocol in Russian schools.

Attacks on schools are rare in Russia. The deadliest school attack in Russia took place in 2004 in the city of Beslan, when Islamic militants took more than 1,000 people hostage for several days. The siege ended in gunfire and explosions, leaving 334 dead, more than half of them children.

In 2018, a teenager killed 20 people at his vocational school before killing himself in the Crimean city of Kerch. In the wake of that attack, Putin ordered authorities to tighten control over gun ownership.

Guns are tightly restricted in Russia. Civilians over 18 can obtain permits for hunting or sports firearms after medical checks. It is illegal to own handguns, guns that shoot in bursts or that have magazines with more than a 10-cartridge capacity.

Most of the measures to tighten gun control proposed after the 2018 rampage — such as raising the minimum age for gun possession, more frequent medical checks for obtaining or renewing a gun permit, and stricter punishments for gun violations — were never implemented.