A gas explosion in a block of flats outside Moscow on Wednesday killed two people and injured five others, officials said.

The blast happened in a nine-storey building in Noginsk, about 30 miles east of Moscow.

It affected the lower part of the building, with three storeys sustaining most damage. About 30 flats were damaged. Local authorities evacuated 170 people from the building.

A man and a woman were killed, and five other people injured, according to the Moscow region’s branch of Russia’s investigative committee.

It was not clear whether there were more people under the rubble.

The authorities launched a criminal probe as is common in such cases. The governor of the Moscow region, Andrei Vorobyov, headed to the site of the blast.