The IOC on Tuesday mourned the death of three French sports stars, including two Olympic medalists, in a helicopter accident during the filming of a reality show.
Olympic swimming champion Camille Muffat, bronze medalist boxer Alexis Vastine and yachtswoman Florence Arthaud were among the 10 people killed when two helicopters collided in Argentina on Monday.
"We are shocked by this sad news," the IOC said in a statement. "Our thoughts are with the families and friends of these great athletes who have left us.
"With them, the world of sport and the Olympic family have lost three of their key members. They were all not only champions in their sport but also contributed greatly as role models."
Arthaud, 57, was one of the first women to carve a place for herself in the top levels of sailing with a 1990 record for the fastest solitary crossing of the Atlantic.
Muffat, 25, won 400-meter freestyle gold at the 2012 London Olympics and silver in 200m while her 4x200 freestyle team won bronze.
Vastine, 28, won bronze at the Beijing Games four years earlier.
"The Olympic movement mourns with their families and friends, their fellow athletes, the French National Olympic Committee and with France," the IOC said.
"The Olympic flag will be flown at half-mast for three days at the IOC headquarters to honor these great champions."
Authorities said it was still unclear what caused the accident in the rugged western province of La Rioja near the Andes Mountains.
Two pilots and several members of the ALP TV production company involved in shooting the adventure show "Dropped" for private TV station TF1 were among the dead, officials said.