The death toll from a building which collapsed north of Cairo earlier on Tuesday rose to 15, reported state-run news agency MENA.
Civil protection forces are still trying to salvage victims stranded in rubble of the collapse, Mamdouh Abdel Qader, head of the civil protection administration, told MENA.
The collapse was due to adding two unlicensed floors to the building, therefore jeopardising its safety, a prosecution official said.
Ibrahim Aql, head of the East Cairo Prosecution for Accidents, said that the prosecution examined the collapsed building and observed renovations conducted on its second floor which also jeoradised its safety.
Building collapses has become a frequent occurrence in Egypt, especially in the coastal city of Alexandria.
A survey conducted by the Cairo-based Egyptian Initiative for Personal Rights (EIPR) in June concluded that 392 residential buildings collapsed in Egypt from July 2012 until June 2013, killing 192 people and rendering 824 families homeless.
The organisation blamed the frequent building collapses on the "lax enforcement" of laws regulating construction as well as the "lack of proper planning and development."