A blast ripped through a five-storey shopping centre in the southwestern Russian city of Ufa on Saturday, starting a fire and injuring three people, the news agency RIA quoted a regional official as saying.
Shoppers were being evacuated and firefighting teams were tackling the blaze at the huge complex, which houses stores, restaurants and night clubs in the largest city in Russia's Bashkiria region, which has a large Muslim population.
Witnesses were quoted as saying flames were flaring out of the windows of the shopping centre.
"Three people were injured and the second and third floors are on fire," said Oleg Zugeev, spokesman of the regional Emergencies Ministry.
An Emergency Ministry official said earlier that there was a danger the roof would collapse.
The cause of the blast was not immediately clear.