Three French sports personalities are among 10 people killed in a helicopter crash in Argentina, the French presidential office confirms.

Eight French nationals and their two Argentine pilots all died when two helicopters collided in La Rioja province in the country's north-west.

They crashed near Villa Castelli, about 1,170km (720 miles) from Buenos Aires, according to local officials.

The helicopters were involved in the filming of TV survival show Dropped.

Long-distance yachtswoman Florence Arthaud, Olympic swimmer Camille Muffat and Olympic boxer Alexis Vastine were confirmed dead by the office of French President Francois Hollande.

Camille Muffat won three medals in the pool at the London Olympics in 2012, while Alexis Vastine took a boxing bronze in Beijing in 2008.

The helicopters were filming Dropped, a popular celebrity show on the channel TF1.

The show flies celebrities into rough terrains by helicopter and films their attempts to find food and shelter.

One of the contestants, former France and Arsenal footballer Sylvain Wiltord, tweeted: "I'm sad for my friends, I'm trembling, I'm horrified, I have no words, I don't want to say anything."

The cause of the crash is unclear. Officials have said the weather conditions in the mountainous area where it happened were good.

"An explosion occurred and it's believed that they must have collided,'' said La Rioja Secretary of Security Cesar Angulo.

"Aeronautical experts will have to determine that," he added.

"We learn with great sadness about the accident during the filming of the Dropped show," said a statement issued by TF1.

"All TF1 teams come together in this terrible time with the pain of the families and relatives of the victims."
(BBC)