The Hewa Bora Airways McDonnell Douglas DC-9 aborted its takeoff on Tuesday from Goma in the east of the Democratic Republic of Congo, then skidded over the runway and down a ravine into a crowded neighbourhood of homes and shops.

North Kivu governor Julien Paluku told Congolese television on Wednesday that 40 people had been confirmed dead so far.

With up to 100 injured, and more than 50 of them still in a serious condition, the death toll could rise, officials said.

A Hewa Bora executive said on Tuesday that bad weather had forced the pilot to abort the takeoff from Goma's notoriously short runway.

"Some passengers have mentioned that all of sudden there was an explosion in one of the engines and the pilot tried to abort takeoff," said Kemal Saiki, a spokesman for the U.N. mission in Congo. "The runway is quite short ... It doesn't have any kind of margin in terms of length." On Tuesday, the governor and the Congolese Red Cross had initially reported only six survivors from the plane and more than 70 dead. But Dirk Cramers, marketing director of Hewa Bora, said most of the 79 passengers and all seven crew had survived.

On Wednesday the nose and cockpit section of the airliner still protruded above the debris of crushed stalls and shattered houses in Goma's Birere district.

Most of the crash victims were on the ground, Saiki said, as the plane plunged through a wall into a crowded market.

Rescue workers toiled through the night using portable generators and high-voltage lamps to pull charred bodies from the wreckage and prevent looting, Saiki said. U.N. peacekeepers have recovered the aircraft's flight recorder.

Congo, a central African state the size of western Europe, has only a few hundred kilometres (miles) of paved roads. But the ageing fleet of often Soviet-built planes that it relies on have one of the world's worst air safety records.

Last September, eight people died when a cargo plane overshot the runway at Goma. Last week, the European Union added Hewa Bora to a list of companies banned from flying there.