A gunman has opened fire at a school in central Russia, killing at least 15 people and injuring 24, Russian officials say.

The victims include 11 children at the school of about 1,000 pupils in the city of Izhevsk.

The gunman killed himself at the scene and was a former pupil of the school.

Videos posted online appear to show panic inside the building where the shooting took place, with children and adults running along corridors.

Other footage shows blood on a classroom floor and a bullet hole in a window, with children crouching down underneath desks.

Eleven children and four adults were killed, including two security guards and two teachers, according to Russia's investigative committee. All but two of the 24 injured people were children.

Staff and pupils have been evacuated from the school building which is in central Izhevsk - a city of about 650,000 residents.

The attacker - named as Artem Kazantsev - is reported to have been armed with two pistols.

A video posted online by state investigators shows the dead body of the gunman on the floor, wearing a T-shirt with a Nazi symbol and a balaclava. Investigators are searching his place of residence.

A mourning period lasting until 29 September has been announced by the head of the region. Russian President Vladimir Putin is "deeply mourning" the deaths and denounced the shooting as an "inhuman terrorist attack", according to his spokesperson.

by Sergei Goryashko, BBC Russian

This latest attack is grimly reminiscent of other school shootings in Russia over the last few years.

The country has seen a number of incidents where either a current student or a graduate has returned to their school and tried to kill as many people as possible.

Previous attacks were carried out with legally-obtained hunting rifles, when getting a licence for such weapons was effectively easier than passing a driving test.

Since the Kazan school shooting in May 2021 and the Perm University attack that September, the authorities toughened the laws. But in this latest atrocity, the attacker used pistols which he could only have got illegally on the black market.

The gunman was dressed in black and had inscribed the word "hate" on his weapons - a bleak echo of the 1999 shooting at the Columbine High School in the US.

Earlier this year, Russia's security services branded as terrorist and banned a group they claimed existed, called The Columbine Movement, which according to them was linked to the Kazan and Perm attacks.