At least 13 people were killed and 20 others feared trapped in the rubble of a run-down apartment block that collapsed "like an earthquake" in Beirut, Lebanese officials and a witness said on Monday.

"We have recovered 13 bodies so far and we believe that about 20 victims remain under the rubble" after the six-storey building came crashing down late Sunday, General Raymond Khattar, head of Lebanon's civil defence, told AFP.

"We hope to find survivors," he added.

He said the bodies recovered include those of three Lebanese, while the rest were mainly Sudanese labourers.

Red Cross official Georges Kettaneh earlier told AFP that 12 people were also wounded when the apartment block in the Ashrafiyeh district of eastern Beirut suddenly collapsed.

Khattar said the building housed some 50 people, including many labourers from Sudan and Egypt. He said at least eight were known to have escaped as the building came down.

Among the dead was a 15-year-old girl, while her grandmother as well as a 73-year-old Lebanese man, at least two Sudanese, an Egyptian and a Filipina were among the injured.

"It was like an earthquake" when the block collapsed, one witness told the local MTV channel.

One resident who escaped with her mother said the building was extremely run-down and the owner had warned tenants not to remain there shortly before it disintegrated.

She told local television that she and her mother managed to escape as the building came tumbling down but her father and three brothers remained trapped.

President Michel Sleiman rushed to the site Sunday evening as did Interior Minister Marwan Charbel and other officials.

Charbel told reporters the building's owner was detained for questioning.

He added it was essential to carry out a survey of similar buildings throughout the country, many of which were built illegally or had several storeys added without proper permits.