Two helicopters carrying passengers filming a popular European reality show crashed in a remote area of northwest Argentina, killing eight French citizens and two Argentines, authorities said.
The helicopters crashed on Monday while flying near Villa Castelli in La Rioja province, about 1,170km northwest of Buenos Aires, La Rioja Secretary of Security Cesar Angulo told television station TN.
All 10 people on board both aircraft were killed.
"An explosion occured and it's believed that they must have collided," said Angulo. "Aeronautical experts will have to determine that".
La Rioja police commissary Fabian Gordillo told state news agency Telam that the dead included two Argentine pilots and eight French citizens.
French President Francois Hollande's office confirmed the deaths of the French nationals. The Elysee Palace said in a statement that famed sailor Florence Arthaud, Olympic swimmer Camille Muffat and boxer Alexis Vastine were among the dead.
The pilots were identified as Juan Carlos Castillo and Roberto Abate.
The mayor of Villa Castelli, Andres Navarrete, said the French nationals were part of a team filming the reality show "Dropped," a survivalist programme with several versions across Europe.
The crew had arrived on Sunday in Villa Castelli, where it had previously filmed a version of the show for Switzerland and Denmark, said Navarrette.
The accident occurred in a rugged, sparsely populated area on the edge of the Andes mountain range that separates Argentina and Chile.