A 17-year-old boy allegedly killed five teenagers and injured four others during a drunken knife attack in the Irkutsk region of Siberia, according to law enforcement officials on Wednesday.

Police investigators reported that the bodies were discovered in a charred house in Baikalsk, located approximately 85 kilometers (53 miles) south of Irkutsk, the regional capital.

“At one point, one individual turned on the others with a knife, resulting in the deaths of four teenagers on the spot, and four others were taken to the hospital,” stated the regional division of Russia’s Investigative Committee.

Of the survivors, three sustained minor injuries, while one remains in critical condition due to stab wounds.

The assailant, whose identity has not been disclosed, reportedly ignited the house after the attacks and perished in the flames, leading authorities to initiate a murder investigation.

Igor Kobzev, the Governor of the Irkutsk region, mentioned that the victims were aged between 13 and 16. He noted that the group had assembled to celebrate a birthday.

Vasily Temgenevsky, the Mayor of Baikalsk, indicated that alcohol contributed to the violent incident.

Health and education officials confirmed that the victims were students from the seventh to tenth grades at two local schools. Regional Education Minister Maxim Parfyonov remarked that the teenagers belonged to “an as yet unidentified community.”

Local authorities have declared three days of mourning.