The gas explosion which took place in the town of Orekhovo-Zuyevo occurred during stay-at-home orders from authorities trying to slow the spread of the coronavirus.
Zhanna Terekhova, a spokeswoman for the emergencies ministry, disclosed in televised remarks that one person was killed and another four were injured when an entire section of the brick building collapsed in the town north of Moscow.
She said 10 flats have been partially destroyed and officials were trying to establish how many people lived there.
The rest of the building appeared intact.
National television broadcast footage of mangled heaps of concrete as a crowd of locals gathered at the scene.
Gennady Panin, head of the Orekhovo-Zuyevo city district, said six people have been pulled from under the debris. Three people were in intensive care, he added in televised remarks.
Moscow region governor Andrei Vorobyov and emergencies minister Yevgeny Zinichev immediately went to the scene of the accident.
Officials have been tasked with evacuating victims to a temporary shelter, Vorobyov’s office said.