Several people have been injured after an explosive device detonated at an Orthodox school near Moscow.
Russian authorities suspect that an 18-year-old former student had blown himself up outside the buildings using a homemade device.
At least 10 people -- including a 15-year-old student -- were injured, authorities have said on Telegram.
The suspected bomber has reportedly survived the blast and is currently in intensive care.
The explosion occurred at a school attached to an Orthodox Vladychny convent in Serpukhov, 105 kilometres outside of the Russian capital.
Staff and students have been evacuated from the scene on Monday morning, the interior ministry for the Moscow region said in a statement. The motive for the incident has not been revealed.
Russia’s Investigative Committee said it had opened an investigation into attempted murder and illegal circulation of explosives
Russian media reports suggest that the teenager may have been motivated by hatred of the teachers and nuns.
Tass news agency has said he was planning an attack during morning prayers, but his explosive device went off at the entrance to the monastery.
Patriarch Kirill, the head of the Russian Orthodox Church, urged support for the victims of the explosion and expressed hope that the authorities would do everything necessary to prevent such an incident occurring again in the future.
Attacks in schools are rare in Russia, but recent shootings have led Russian President Vladimir Putin to call for weapons laws to be tightened.
Four months earlier, a 19-year-old opened fire in his old school in the central city of Kazan, killing nine people.