LAGOS: Nigeria recovered more bodies, searched for clues on the cause and declared three days of national mourning on Monday after an airliner crashed in a densely populated area of Lagos overnight, killing all 153 people on board.

President Goodluck Jonathan visited the crash site in Nigeria's commercial hub and saw emergency services working amid the smouldering, ash-covered wreckage of the McDonnell Douglas MD-83 flown by privately owned domestic carrier Dana Air.

Jonathan ordered an investigation into how the plane crashed into the iron roof of an apartment block in the residential suburb of Agege. Search teams found what they believed to be the plane's “black box” flight recorder, said an official.

“This particular incident is a major setback for us as a people ... Investigations will have to be done thoroughly to ascertain what was the cause of the crash,” he told reporters. Jonathan, who arrived in an armoured convoy with Lagos state governor Babatunde Fashola, got out and walked the last few metres (yards) on foot in his traditional Nigerian kaftan and skull cap to the crash site.

The airline said on Sunday 147 people had been killed but in a list published overnight there were also six crew members on board, taking the death total to 153. An unknown number of people may have been killed on the ground.

“They're still busy recovering bodies. I believe some people were killed on the land as well as on the plane, though we don't yet have a precise idea of numbers,” said Tunji Oketunbi, a spokesman for Nigeria's Accident Investigation Bureau.

Oke Osanyintolu, head of the Lagos State Emergency Management Agency, told Reuters at the scene that 80 bodies had been pulled out by about 12:30 p.m. (1130 GMT).

A crane was helping to clear away some of the debris.

“This is really a horrific moment for us here and we sympathise and give condolences to all the victims and families,” said Fashola. “(There are no) words to express our pain and grief. It is saddening, it is simply too much.”

A source at Dana, who asked not to be identified, said the plane was manufactured in 1983.