Lance Armstrong of the U.S. is seen in an ambulance as he arrives at Hospital Clinico in Valladolid, Spain, Monday March 23, 2009. [Xinhua/Reuters Photo]?

Seven times Tour de France winner Lance Armstrong was taken to hospital on Monday after breaking his collarbone in the Tour of Castilla-Leon.

The American was involved in a group fall with several other riders 20 km from the finish in the town of Baltanas, during the first stage of the five-day stage race, which is being held in central Spain.

He was riding in Spain to prepare for three-week Tour of Italy (Giro d'Italia) in May and subsequently the Tour de France in July.

TV images showed the American sat on the roadside holding his right arm. He was forced to abandon the race as an ambulance took him to hospital in Valladolid.

Tests there showed that he had suffered a clear break in his collarbone. It is a common injury in cycling and one that will keep him out of action for around six weeks.

It will be almost impossible for him to race in Italy and his presence in this year's Tour de France could also be in doubt.

Armstrong returned to cycle racing with the Astana team this season, after missing the past three years through temporary retirement.

(Xinhua News Agency March 24, 2009)