The building collapsed Monday morning after most of the residents had left for work. In the first 24 hours after the collapse, three people were pulled out alive.
The building, which originally had seven floors, was built some 25 years ago without planning permission. The building's owner later secured a permit, but then illegally added a further five floors to the apartment block. The building was recently declared to be unsafe, and had been scheduled for demolition.
Prosecutors have issued an arrest warrant for the building's owner and council officials following the collapse.
Safety violations have been the cause of numerous recent building collapses in Egypt. In November 2006, seven people died following the collapse of a four-story building in the city of Mansura in northern Egypt. A year earlier, the illegal addition of three floors to a residential building in Alexandria left 19 dead.