NOUMEA, New Caledonia (AFP) - A young French professional cyclist was killed in a collision with an ambulance at a race in New Caledonia, organisers said Friday, a crash that also broke the leg of his teammate.

Mathieu Riebel, 20, was killed instantly in the horror smash at the Tour de Nouvelle-Caledonie - an annual 870 kilometre (540 mile) race across the French pacific territory.

His teammate Erwan Brenterch, 31, also suffered a broken leg in the accident, which occurred during a descent section on the western edge of the main island.

"The race has been stopped and I don't know if we will resume tomorrow," Gerard Salaun, president of New Caledonia's regional cycling committee said.

The exact cause of the crash was still to be determined, Salaun said.

But he added that one of the cyclists is believed to have cut a corner.

The accident took place on the first stage of the tour which began on October 13 with 62 riders.