The building collapsed on to the street
Witnesses said the building collapsed forwards, showering chunks of concrete into the street, crushing several passers-by and burying at least two vehicles.
The building, a seven-storey school, is located on the Corniche Mazraa, a busy boulevard in a densely populated area of the city. It "turned into a pile of rubble", officials said.
The cause of the collapse, which occurred at 1230 local time (1030 GMT), is not yet known. But construction workers had been carrying out restoration work on the building.
Trapped victims
One of the dead was said to be a construction worker, another a man who had been driving along the street when the building fell onto his car.
Police also said the bodies of two young women were found in a car that was passing the building at the time it collapsed.
Rescue workers had feared that as many as 12 other people might be trapped in the debris.
However as night fell, rescuers had cleared much of the rubble and said they did not expect to find any other casualties there.
Building 'imploded'
Police said approximately 15 construction workers were in the building when it collapsed.
"First of all we felt a little quake and then we heard a rumble," said local shop-owner Sanaa Mustafa al-Hakim, quoted by Reuters news agency.
"We looked outside and we saw the building swaying like a cardboard box. It started to implode, then it fell outwards on to the street and the roof landed right in front of my shop."
The building, which was being renovated after damage during the 1975-1990 civil war, housed a school.
Some witnesses said classes were in progress at the time, but others and a Lebanese security source said no children were inside the building when it collapsed.
Workers used pneumatic drills to break up concrete slabs that had fallen on two cars and bulldozers were brought in to start clearing debris.
Rescue workers managed to pull one man out of the rubble alive and apparently uninjured.