A 16-storey building collapsed on Indira Gandhi Street in central Dar es Salaam on the morning of 29 March, trapping dozens of people under the rubble.
There are conflicting reports about the number of casualties, with local newspaper The Citizen quoting regional police commander Suleiman Kova as saying that 15 individuals were killed.
The BBC reports that there were three casualties and that 13 people have been saved from the rubble. It says that there could be as many as 45 people missing, including construction workers, residents and children from a Koranic school.
Rescue workers are being assisted by a crane but most of the excavation is being done by hand, and some of those trapped have been able to make contact using their mobile phones.
The building was under construction in Dar es Salaam's central business district.