IOC President Thomas Bach says the Olympic world is in mourning for the three French athletes killed in a helicopter crash in Argentina.

Olympic swimming gold medalist Camille Muffat, boxing bronze medalist Alexis Vastine and pioneering sailor Florence Arthaud were among the 10 people killed when two helicopters filming a reality TV show crashed Monday.

Bach says Tuesday: "We are shocked by this sad news. Our thoughts are with the families and friends of these great athletes who have left us."

Bach says "the world of sport and the Olympic family have lost three of their key members."

He adds the athletes "were all not only champions in their sport but also contributed greatly as role models."

Bach says the Olympic flag will be flown at half-staff for three days at International Olympic Committee headquarters.