The infections are the first confirmed by the French army among soldiers serving in its foreign operations.

Colonel Frederic Barbry, the spokesman for the French armed forces chief of staff, told AFP one of the soldiers was being treated in his country of deployment, while the other three have been repatriated.

The group had arrived in the area several weeks ago and were not showing symptoms, he said. People they had been in contact with were being placed into quarantine but military operations were continuing as normal, said Barbry.

The 5,100 strong-Barkhane force fights jihadists in cooperation with the Sahel countries of Mali, Burkina Faso, Niger, Mauritania and Chad.

France last week said it will withdraw its contingent of troops from Iraq, mostly trainers to local armed forces, because of the coronavirus pandemic.