MOSCOW (AP) — A gas explosion in a residential building in southern Russia on Thursday killed five people and injured another four, local emergency officials said.

The blast occurred early in the morning in the city of Cherkessk in the Karachay-Cherkessia region, which borders Georgia, about 1300 kilometers (800 miles) south of Moscow. The explosion severely damaged two upper stories of a five-story residential building, the emergency officials said, and the building could crumble even further.

Russian law enforcement has launched a criminal probe, suspecting safety violations. Gas explosions in residential buildings are fairly common in Russia.

In August, a gas explosion destroyed a section of a five-story residential building in the Ural Mountains, killing 11 people. At the time, the Russian state news agency Tass reported that between the beginning of 2022 and Aug. 1, 2024, at least seven such explosions occurred, killing a total of over 50 people.