Screenshot: the Russian Investigative Committee

A Russian teenager stabbed four of his friends to death at a house party in Siberia’s Irkutsk region in the early hours of Wednesday, before setting fire to the house and dying in a subsequent gas explosion, according to Russian law enforcement and local media.

Five bodies were found in the burnt-out house in the city of Baykalsk on Wednesday morning, the Russian Investigative Committee said, adding that four more teenagers were taken to hospital with stab wounds.

According to the investigation, “a group of young people” were holding a party at a private house when one of the attendees attacked the others with a knife. He then set fire to the house, causing the gas explosion. A criminal case has been opened into the murders of two and more people.

Local media reported that all of the teenagers, aged 13 to 17, who attended the party went to the same school. While the Russian authorities did not name the perpetrator, VCHK-OGPU, a Telegram channel with ties to the security services, named him as Mikhail Paramonov, a 17-year-old who had hosted the party at his older brother’s house.

According to the channel, 14 teenagers attended the party, five of whom had gone home before the attack took place. A video from the party posted by Telegram channel Mash appears to show several bottles of strong liquor on the table, as one of the attendees says “We’re partying hard tonight”.

At some point during the night, Paramonov began stabbing his friends with a box cutter knife while they were asleep, possibly motivated by anger after a girl he knew, 14-year-old Viktoria, rejected his sexual advances, the channel wrote.

According to Telegram channel Baza, four teenagers were killed in the stabbing and the ensuing fire — Polina, 16, Oybek and Vadim, both 14, and 13-year-old Nikolay. Viktoria reportedly survived the attack, managing to run out of the house just before Paramonov turned on the gas to set fire to the house.

Regional governor Igor Kobzev called the incident “truly shocking” in a post on Telegram on Wednesday, declaring a three-day period of mourning in Baykalsk and vowing to support the injured teenagers and the victims’ families.