Armstrong heads for US home after accident

American cycling legend Lance Armstrong left Spain for his home in Texas Tuesday a day after suffering a broken collarbone during a race.

"Sitting in the airport getting ready to fly home. Layover in NYC then ATX!" (Austin, Texas), Armstrong said on the social networking site Twitter.

The 37-year-old thanked "everyone here in Spain for all the help and support."

The rider broke his collarbone when he fell along with several other riders about 20 kilometres (32 miles) from the finish line of the first stage of the Tour of Castilla y Leon in central Spain on Monday.

The rider said after leaving hospital late Monday he felt "miserable" over the accident, which places a serious question mark over his participation in the Giro d'Italia in May and threatens to disrupt his preparations for the Tour de France in July.

Armstrong, a cancer survivor who went on to claim a record seven Tour de France crowns, ended a three-and-a-half year retirement at the Tour Down Under in Australia in January.

He declared his goal this year is to win an eighth Tour de France title in July, and had hoped to use the Castilla y Leon race as part of his preparations.