MADRID (AFP) - A jet belonging to a Spanish airline skidded off a Madrid airport runway and crashed in flames on Wednesday, killing at least seven people and injuring dozens, media reports said.

The Spanair jet made an emergency landing just after taking off from the Madrid-Barajas airport, according to an emergency services spokesman quoted by national radio.

Cadena Ser radio said seven people were killed and 20 injured in the crash while El Mundo newspaper said eight people were killed on the flight heading to Las Palmas in the Canary Islands.

Billowing smoke poured from the wreckage of Flight 5200 off the bottom of the airport's runway four after the crash.

An airport spokesman said the jet had a capacity of 166 passengers.

Spanair, a subsidiary of Scandinavian carrier SAS, is Spain's second biggest airline after Iberia. Five passengers on a Spanair flight from Spain's Basque region to Barcelona were injured in an emergency evacuation on January 9, 2006.

It was founded in 1986 and says it has carried more than 104 million passengers from about 100 European destinations to Spain since then. It is a member of the Star Alliance network but recently proposed shedding almost a quarter of its 4,000 staff because of the the fuel price rise crisis.

The airline posted net losses of 41 million euros (62 million euros) in the first quarter.