Firefighters, rescue teams and police and rescuers rushed to the 22-story building in Shantinagar, a district developed in the 1960s and 1970s, after a storm with winds gusting up to 80 kph (50 mph) lashed the area.

"When the storm hit, we felt the building was falling and we rushed out," Hosne Ara, a housewife said as she stood weeping outside the building.

The incident raised new questions about building standards after Thursday's fire that raced through the centuries-old Kayettuli district, a warren of narrow streets, multi-story blocks and tin-roofed dwellings, killing at least 117 people.

With rescue operations after the fire now declared ended, some of the more than 100 injured remained in critical condition in hospitals.

Flags flew at half mast, television played sombre music and grieving relatives gathered at gravesites as the authorities declared a national day of mourning.

Dhaka is a bustling city of 12 million, but many buildings are poorly constructed because of lack of supervision and circumventing of regulations.

Dhaka's mayor promised action to ensure safety.

"The building authority for the capital Dhaka RAJUK has a list of 5,000 poorly built buildings and soon those structures will be pulled down," Sadek Hossain Khoka said outside the cracked building.

But an engineer with the building authority said demolitions were often hindered by action in the courts.

Officials have suggested that narrow roads and a lack of proper fire escapes contributed to the high death toll and some groups have called for an immediate improvement in standards and a crackdown on bribe-taking in the building trade.

"The authorities must ensure adequate standards for each building for the safety of the users," Quamrul Islam Chowdhury, a leader of the Bangladesh environment journalists group, said in a statement.

Last Tuesday, 25 people were killed and 50 injured when a building collapsed in the capital's Begunbari area.