MOSCOW — Russian authorities say that a gas explosion in an apartment building in Russia’s south has killed at least two people and injured eight others.

The Russian emergency situations ministry said that an entire stairwell in the building in Volgograd collapsed in Tuesday’s blast.

Andrei Bocharov, governor of the Volgograd region, said in televised comments that two people have been confirmed dead, eight injured. Three of them are hospitalized in serious condition.

Footage from the scene showed firefighters and emergency workers clearing the rubble at the four-story building with the entire stairwell missing.

Bocharov said that investigators believe that the explosion occurred after one of the tenants tried to get connected to the gas grid without proper authorization.