Rescue teams battled to free 15 people trapped in the rubble of a Cairo apartment block early Tuesday after it collapsed during the night, killing at least 10 others.
The Egyptian capital's emergency services chief General Mamduh Abdelkader said that investigators were still probing the cause of the collapse in the poor eastern neighbourhood of Matariya but that illegal construction work was suspected.
"Ten people have been killed and we fear that number may rise as 15 people are trapped in the rubble," Abdelkader told AFP.
"We don't yet know the cause of the accident but we have been told that two storeys were recently added totally illegally."
Deadly building collapses are not uncommon in Egypt, where safety and planning regulations are widely flouted.
Landlords often add extra floors to buildings whose foundations