Gas explosion in Russian apartment building kills 6, including 2 children

In this photo provided by the Yaroslavl Branch of Russian Emergency Ministry Press Service, emergency and rescue workers search the debris of a 5-story apartment building after a powerful natural gas explosion early Tuesday, Feb. 16, 2016, in Yaroslavl, Russia. (Russian Emergency Ministry Yaroslavl Branch Press Service via AP) (Russian Emergency Ministry Yaroslavl Branch Press Service via AP)

An explosion of natural gas in a five-story apartment building in a central Russian city has killed at least six people, including two children, and injured nine others, the emergency services said.

The explosion before dawn Tuesday in Yaroslavl, a city 250 kilometers (160 miles) northeast of Moscow, destroyed five apartments and damaged 20 others in the building, the emergency services said.

All residents of the building were evacuated, a total of about 130 people. It was unclear whether all residents had been accounted for or whether any were missing.

Most apartment buildings in Russia are supplied with natural gas for cooking. The cause of Tuesday's explosion was under investigation.