At least 12 people have been killed and seven injured after a block of flats collapsed in Cairo.

Sources say the casualty figure is expected to rise as rescue workers search for survivors that are feared to be trapped under the rubble of the eight-storey building in the western suburb of Matriya.

Residents have been evacuated from nearby buildings.

The cause is not yet known, but an unnamed official source told Aljazeera news that the collapse may have been caused by the "unauthorised construction" of extra levels on the building.

Building collapses are common in Egypt because of illegal construction, especially in shanty towns, poor city neighbourhoods and rural areas.

building collapse in cairo
People and rescue workers carry a body which was removed from the site of a collapsed eight-storey building in the Cairo suburb of Matariya Reuters