The Russian Police have arrested a 15-year-old boy for attacking a group of younger students with an axe, injuring six people, before throwing a Molotov cocktail and setting a schoolroom on fire, Reuters reported on Friday.

Five students from the seventh grade and one teacher were injured in the attack by a ninth-grade student at the school in Sosnovy Bor village, just outside the south Siberian city of Ulan-Ude.

“The boy threw a Molotov cocktail in the class on the third floor, cut off a girl’s finger and wounded another,” The Siberian Times quoted an unidentified witness as saying. The daily later reported that the main attacker had an accomplice, who is still on the run.