MOSCOW, March 26 (Xinhua) -- At least 53 people were killed in a fire at a shopping mall in the south central Russian city of Kemerovo, Russia's Emergency Situations Ministry said Monday.

The fire, which started Sunday afternoon, has been put out, but rescuers are still struggling to reach the upper floors because the roof of the building collapsed.

A spokesperson of Russia's Investigative Committee said 11 people injured in the fire were currently being treated in hospital and over 40 have asked for medical help due to the fire, according to a report by Sputnik.

TV images showed black smoke billowing from the Winter Cherry shopping center, a business complex that also houses a cinema which is usually packed with audience on Sunday afternoons.

According to an earlier statement by the Emergency Ministry, specialists participating in the search and rescue effort said the work at the scene is complicated by dense smoke, severe gas contamination, high temperatures, as well as unstable structures.

Some 120 people were evacuated from the mall following the fire, rescuers said.

Russian Emergencies Minister Vladimir Puchkov said the first stage of search and rescue operations will be completed by 6:00 p.m. local time (1100 GMT).

It still remains unclear what caused the fire at the shopping mall.