A 14-year-old girl shot a classmate dead and injured five people before killing herself at a secondary school in the Russian city of Bryansk near the Ukraine border on Thursday.
Fatal attacks at educational facilities -- previously a rarity -- have become more common in Russia in recent years.
Moscow has taken steps to tighten already strict gun laws after a series of school attacks. After the Bryansk attack, the Kremlin said it would look into "why the measures did not work".
Moscow has voiced concern after previous attacks, with President Vladimir Putin calling the incidents a US import.
"A 14-year-old girl brought a pump-action shotgun to school, which she used to shoot her classmates," Russia's Investigative Committee said in a statement.
"As a result, two people died -- one of them the shooter -- and there are five wounded," it added.
The victim was another girl in the shooter's class. Authorities did not identify the attacker and Russian media named her only as "Alina."
Footage filmed by pupils and shared by Russian state TV showed panicked children screaming and the sounds of a loud explosion.
Another showed students barricading themselves inside a classroom.
The state-run TASS news agency reported that law enforcement believed there was an conflict between the shooter and the victim. It also reported that girl had used a hunting rifle owned by her father.
The shooting took place in Bryansk's Gymnasium Number Five, a secondary school in the city's suburbs.
News agencies reported that the girl's father had been taken in for questioning and that the family's apartment was searched.
State media also reported that the girl's twin sister was also in the class, reporting that she was in shock.
Local news outlets meanwhile reported that the girl had come to school with a gun and a knife.
The Investigative Committee published a video of detectives assessing the classroom, which still had open textbooks and blood on the floor, confiscating phones and looking at laptops.
The governor of the Bryansk region, Alexander Bogomaz, called the shooting a "terrible tragedy".
"My sincere condolences to the parents of the girl who died at the hands of the girl shooter. This is an irreparable loss," he said.
Bogomaz said five minors were wounded with light and medium-severe injuries and taken to a local children's hospital.
Media later reported that one of the wounded teens, a boy, was in serious condition and had been taken to Moscow for treatment.
Bryansk is a city of around 370,000 people in southwest Russia.
The border region -- including Bryansk itself -- has recently been targeted by Ukrainian drone attacks and occasional shelling.
Russia has tightly controlled its school system since sending troops to Ukraine, making patriotism a priority and teaching children about its offensive in Ukraine.
Russia tightened its already strict gun ownership laws following a series of school shootings between 2019 and 2021.
In the western Russian city of Izhevsk in September last year, a gunman killed 18 people at a school.
In 2021, a 19-year-old shooter killed nine people in a school in Kazan, and the same year a teenager killed six people at a university in the Urals city of Perm.
