MOSCOW, December 9. /TASS/. An explosion was reported at the Mega Khimki shopping mall, followed by a collapse of supporting structures, sources at rescue services told TASS on Friday.

"An explosion occurred at the OBI hypermarket of the Mega Khimki shopping mall, followed by a collapse," a source said.

According to a rescue source, the area of the collapse was around 5,000 square meters.

The press service of the Russian emergencies ministry told TASS that firefighting aviation crews were put on alert and ready to join the effort.

Besides, Moscow firefighting units have departed to the city of Khimki northwest of Moscow to assist in tackling the blaze.