A Russian teenager tried to blow himself up at an Orthodox school near a 14th century convent outside Moscow on Monday, wounding at least another student, the interior ministry said.
Russia has seen a rise in similar attacks on schools in recent years but incidents at religious premises are rare.
“An 18-year-old graduate of this educational institution entered the premises of the Orthodox gymnasium of the Vvedenskiy Vladychniy convent and blew himself up,” it said in a statement.
A 15-year-old was injured in the attack in the city of Serpukhov, 100 kilometres (60 miles) south of Moscow, the statement said.
According to preliminary information, the perpetrator was not killed in the blast, it said.
The ministry said the staff had been evacuated and that “information about other victims” was being clarified.
Several Russian news agencies said that up to seven people were injured. The school teaches children from the ages of 7 until 16.
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.
“All the services reacted on time, doctors helped injured children and there is no threat to their lives,” he said on Telegram.
Moscow prosecutors posted a video from the scene with police and ambulances outside the convent in snowfall.
It also posted a video of a local prosecutor from inside the school with Orthodox icons in the background.
The Investigative Committee, which probes major crimes, said it had opened a criminal case into attempted murder and the illegal handling of explosives.
The Committee also said it had sent detectives to the scene.
The monastery was established in 1360.
Rise in teenage attacks
Since President Vladimir Putin first came to power in 2000, the Russian church has enjoyed vastly increased influence.
It has increased its influence on traditionally secular institutions such as schools, with lessons on religion and clerics lobbying for conservative textbooks.
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.
In October 2018, another teenage gunman killed 20 people at a Kerch technical college in Crimea, the peninsula Russia annexed from Ukraine in 2014.
The attacks have led some in Russia to call for stricter gun control in the country and for reinforced security in schools.