Moscow: A gunman with a swastika on his t-shirt killed 13 people, including seven children, and wounded more than 20 at a school in Russia on Monday before committing suicide, investigators said.

Russia's Investigative Committee, which handles major crimes, said it was looking into the attacker's suspected neo-Nazi links. It named him as Artem Kazantsev, a man in his early thirties, and said he was a graduate of the school.

"Currently investigators...are conducting a search of his residence and studying the personality of the attacker, his views and surrounding milieu," the committee said in a statement. "Checks are being made into his adherence to neo-fascist views and Nazi ideology."

Investigators released a short video showing the man's body lying on the floor of a classroom with overturned furniture and papers strewn on the bloodstained floor. He was dressed all in black, with a red swastika in a circle drawn on his teeshirt.

The committee said the six adult victims included teachers and security guards. It said 21 people, including 14 children, were wounded.

Tass news agency quoted investigators as saying the attacker was armed with two pistols and a large supply of ammunition.

Kremlin spokesman Dmitry Peskov said President Vladimir Putin "deeply mourns" the deaths. He described the incident as "a terrorist act by a person who apparently belongs to a neo-fascist organisation or group".

He said doctors, psychologists and neurosurgeons had been sent on Putin's orders to the location of the shooting in Izhevsk, about 970 km (600 miles) east of Moscow.

Russia has seen several school shootings in recent years.

In May 2021, a teenage gunman killed seven children and two adults in the city of Kazan. In April 2022, an armed man killed two children and a teacher at a kindergarten in the central Ulyanovsk region before committing suicide.