CAIRO — An apartment building in Cairo partially collapsed overnight, killing at least four people, Egyptian officials said Monday.

By late morning, rescue workers were still searching for a possible survivor trapped under the rubble of the four-story building in the densely populated Roud el-Farag neighborhood of the Egyptian capital. A fire engine ladder was used as rescuers tried to enter the part of the building that was still standing.

The dead were all from one family, the state-run Al-Ahram daily reported. The report said part of the building's stairs collapsed as rescue workers were searching the rubble, injuring a policemen.

Four others, including a child, were pulled from under the rubble and taken to a hospital, said the officials, speaking on condition of anonymity because they were not authorized to talk to the media.

Police cordoned off the area, keeping back onlookers and those who were apparently looking for relatives in the building. Authorities also evacuated neighboring buildings for fear of others collapsing.

It was not immediately clear what caused the collapse. It is not uncommon for buildings to collapse in Egypt, where shoddy construction is widespread in shantytowns, poor city neighborhoods and rural areas. In December, five people were killed when an apartment building collapsed in Alexandria.

With real estate at a premium in big cities such as Cairo and Alexandria, developers seeking bigger profits frequently violate planning permits. Extra floors often, for example, are sometimes added without proper government permits.

The government has recently launched a crackdown on illegal construction across the country, jailing and fining violators, and in many cases demolishing the buildings.