At least 25 people are now known to have died after a multi-storey building collapsed in the main Tanzanian city of Dar es Salaam, officials say.
Hopes are now fading to find a number of missing people said to be trapped in the rubble following Friday's collapse.
It has been more than 46 hours since the last of 18 survivors were found.
At least four people - reportedly the building's owners and construction officials - have been held for questioning by police.
A police investigation into the cause of the accident is continuing.
Tanzanian President Jakaya Kikwete - who visited the scene on Friday - has expressed condolences to the victims' friends and families.
The building - which was still under construction and supposed to have been at least 12 floors high when finished - collapsed on Friday morning.
Eyewitness Nishit Surelia told the BBC: "There was a huge noise and the building collapsed behind me.
"Everyone started running, thinking it was an earthquake. There was dust everywhere. We then realised what had happened."
The collapsed building was near a mosque, as well as other residential and commercial properties in central Dar es Salaam.
Tanzania's growing economy has prompted a construction boom in the city in recent years, as in many African cities.
But correspondents say the speed of construction and lack of safety standards sometimes put at risk both the buildings and those living and working in them.