A Russian teenager has detonated an explosive device at an Orthodox school near a convent outside Moscow, injuring a number of people.

Russia's interior ministry says an 18-year-old man, a graduate of the school in Serpukhov, tried to blow himself up. He has reportedly survived.

The ministry says a 15-year-old is among the injured. Local media say as many as eight people are hurt.

Russia has seen a rise in attacks on schools by teenagers in recent years.

Local media reported that the man who set off the explosives was in a critical condition in hospital. He has been named as Vladislav Struzhenkov, BBC correspondents report.

Russia's Interfax news agency cited a source as saying the teen's animosity towards teachers and students at the school may have motivated the attack.

Another source told Tass news agency the former high school student was planning an attack during morning prayers, but his explosive device went off at the entrance to the monastery.

Prosecutors in the Moscow region have opened an attempted murder investigation - but the motive for the attack is yet to be officially confirmed.

The prosecutors posted a video from the scene showing police and ambulances outside the convent.

The governor of the Moscow region, Andrei Vorobyev, did not specify how many students were injured but said none were in a life-threatening condition.

In a Telegram post, he said "all services reacted on time" and "doctors helped injured children".

The Vvedensky Vladychniy Monastery in Serpukhov was founded in 1360. Children between seven and 16 are taught at the school, about 100km (60 miles) south of Moscow.

Pavel Aksenov and Maria Kiseleva, BBC Russian, Serpukhov

The Vvedensky Vladychniy convent is an ancient complex on the outskirts of Serpukhov. Its red battlement wall is reminiscent of the Kremlin in Moscow.

Now the gate to the convent is guarded by riot policemen in black helmets and flak jackets. But only this morning, it was guarded by a couple of middle-aged guards, watching the CCTV feeds inside their cabin.

One of them tells us he heard the explosion but made nothing of it. "The sound wasn't very loud, I thought perhaps it was something exploding by the river, they sometimes blow up ice there."

Another guard says that had the attacker been able to get inside the school, the number of casualties would have been far greater. "Mother Klavdiya phoned the emergency services, and everything has been cordoned off," they explain.

The convent school has both female and male pupils and all of them were evacuated soon after the attack.

Incidents at religious facilities are rare in Russia, but the country has seen a rise in teenage attacks on schools in recent years.

In September, a student killed six people and wounded dozens on a university campus in the Urals city of Perm.

In May, a 19-year-old opened fire in his old school in the central city of Kazan, killing nine people.