Survivors still trapped after deadly Tanzania building collapse

Tanzanian rescue workers have dug through the ruins of a collapsed building for a second day, hoping to pull survivors from beneath the rubble.

The four-storey block came down at around 0600 GMT on Saturday in the east African country's busy Kariakoo market, in the centre of the commercial capital Dar es Salaam.

Five people have been confirmed dead from the disaster, the fire brigade said. At least 70 people had been retrieved alive from the site.

Dar es Salaam regional commissioner Albert Chalamila said on Sunday that there were more people still trapped in the basement floor of the shattered building, without specifying how many.

"We are communicating... and already we have supplied them with oxygen and water," he said.

"They are stable and we believe they will be rescued alive and safe."

A mountain of debris

The fire brigade chief John Masunga said the search and rescue had been hampered by the many walls making up the structure of the building.

After the building's floors rapidly buckled beneath each other until they formed a mountain of debris, hundreds of first responders used sledgehammers and their bare hands to pull away masonry for hours.

Cranes and other heavy lifting equipment were then brought in to help.

It is not clear why the commercial building collapsed but witnesses told local media that construction to expand its underground business space began on Friday.

The incident has renewed criticism over unregulated construction in the city of Indian Ocean, which has more than five million people.

One of the world's fastest-growing cities, Dar es Salaam has been the scene of a frenetic property boom with buildings shooting up at speed, often with scant regard for regulations.

In 2013, a 16-storey building collapsed in Dar es Salaam, killing 34 people.