MOSCOW (AP) — A homemade bomb detonated in a school attached to an Orthodox convent has wounded 12 people, including a 15-year-old, Russian authorities were reported as saying said Monday.

They said the suspected bomber was an 18-year-old former student of the school. The man survived and is currently in intensive care.

The explosion occurred in the Vladychny convent in Serpukhov, 105 kilometers outside of Moscow, Russian state news agency TASS reported.

Media reports suggest that the teenager may have been motivated by hatred of the teachers and nuns.

Staff and students have been evacuated from the scene. Russia’s Investigative Committee has opened an investigation.