At least nine people were killed and others injured when a four-storey building collapsed overnight in the Moroccan city of Fez, the city's prosecutor said on Thursday.

Residents of adjacent buildings in the densely populated neighbourhood were asked to evacuate as a precaution against potential further collapses, while a search for potential survivors was still under way.

By midday, six people had been rescued from the rubble of the building, which was built in the 1980s, Al Oula state television reported.

Fez, a former capital dating back to the eighth century and the country's third-most-populous city, has seen similar incidents in recent months, including one in December when two buildings collapsed, killing at least 22 people.

At risk of collapse

In 2010, the collapse of a minaret in the historic northern city of Meknes killed 41 people.

Adib Ben Ibrahim, housing secretary of state, said last year that approximately 38,800 buildings across the country had been classified as being at risk of collapse.