A 12-story building collapsed Monday in Egypt's Mediterranean port city of Alexandria, killing at least five people, a police official and witnesses said.

An old woman was pulled out alive from under the debris, the police official said.

The official, speaking on condition of anonymity because he is not authorized to speak to the media, said residents were still believed trapped under the piles of bricks and concrete slabs of the building in the eastern Al-Raml district of the city.

Police could not immediately explain the reasons for the fall of the building, said to have been built in 1978. The police official said the building originally had seven stories but that the five additional ones were built in recent years.

Buildings regularly collapse in Egypt, either as a result of deterioration with time or shoddy construction that fails to meet standards and regulations. Also, some owners tend to illegally add on more stories to buildings.