MADRID (AFP) - - A Spanish tourist jet carrying 172 people careened off a Madrid airport runway and broke up in flames on Wednesday, killing 153 people in the country's worst air crash in more than 20 years, the government said.

One engine of the Spanair MD-82 caught fire during the attempted take-off from Madrid-Barajas airport on a flight to Las Palmas in the Canary Islands at 2:45pm (1245 GMT), Spanish media said, quoting witnesses.

Smoke billowed from the wreckage of Flight JK 5022. Helicopters dropped water to douse the flames of the jet and grassfires caused by the crash.

The airport cancelled departures after the crash and restricted the number of flights arriving. About 30 incoming flights were delayed by up to seven hours.

Transport Minister Magdalena Alvarez said 153 people were killed among the 172 people on board, 10 of them crew members.

She told a news conference that 19 people were injured, 17 of whom had been identified.

The head of the emergency and rescue services in Madrid, Ervigio Corral, earlier said the bodies were scattered over a wide area, and some of the survivors were able to "walk away" from the accident.

At least 50 emergency service vehicles were at the scene.

Spanair, Spain's second largest airline after Iberia, said the names of the passengers and crew would only be released after families have been notified.

"Information on the number of people involved is not yet available, but Spanair is doing everything possible to help the Spanish authorities at this difficult time," the company added.

The flight was a codeshare with Lufthansa and the German carrier said four passengers from a Lufthansa flight were registered on the ill-fated Spanair jet and had arrived in Madrid.

The Swedish foreign ministry said two Swedes were among those on board, at least one of whom survived.

At the airport, friends and family members of those on board were escorted into a special room, where priests were present. Dozens more distraught friends and family waited at Las Palmas airport.

Spanair's managing director Marcus Hedblom described it as "the worst thing that could happen" and expressed his condolences to the families of those killed.

SAS, the Scandinavian airline which owns Spanair, said a special team had been set up in Madrid. "SAS is doing everything possible to help passengers and next of kin and to assist Spanish authorities."

Spanish Prime Minister Jose Luis Rodriguez Zapatero interrupted his holiday to go to the scene, his office said.

The Boeing Co., which owns McDonnell Douglas, offered assistance to Spanish authorities investigating the disaster.

It was the deadliest air accident in Spain since February 1985, when 148 people were killed in a crash in the northern city of Bilbao.

The most deadly accident in Europe's aviation history remains the collision between two Boeing 747s at Tenerife airport in Spain's Canary Islands on March 27, 1977 with 583 victims.

Spanair has had a good safety record until now.

However, five passengers on a Spanair flight from Spain's Basque region to Barcelona were injured in an emergency evacuation on January 9, 2006.

The airline was founded in 1986 and says it has carried more than 104 million passengers from about 100 European destinations to Spain since then. It has a fleet of 65 jets.

The carrier, a member of the Star Alliance network, recently proposed shedding almost a quarter of its 4,000 staff because of the fuel price rise crisis and reduced demand.

It posted net losses of 41 million euros (62 million dollars) in the first quarter.

SAS shares plunged 6.41 percent on the Stockholm stock exchange after the crash.

SAS had put Spanair on the block earlier this year but announced in June that it was abandoning the sale plans due to the slowdown in the aviation sector.