An armed student who entered a school in Moscow and shot dead two adults before taking more than 20 teenagers hostage has been arrested.

Police said the student had killed one officer and a teacher. Another policeman was shot and injured.

The hostages were freed after the student’s father went in to the school.

Russian President Vladimir Putin has described the incident as “tragic”, while Moscow’s mayor called for a review of school security.

Russian investigators named the suspect as Sergei Gordeyev, and said he was an excellent student who appeared to have had an “emotional breakdown”.

He was armed with two rifles legally owned by his father.

Vladimir Markin, a spokesman for Russia’s main investigative agency, said a school security guard had been unable to stop Gordeyev from entering the school when he arrived carrying the weapons.

But the guard did manage to hit an alarm before following the student to his classroom, he said.

Gordeyev shot dead a geography teacher before locking more than 20 10th grade students – aged about 15 – inside a classroom.

He then fired at least 11 shots at police officers who had responded to the alarm, wounding one and killing another, Mr Markin said, in the statement quoted by Russian news agencies.