"Over 30 members of armed terrorist groups were neutralised," the military said, a term meaning that they were killed or captured.

A French military doctor was also killed during the operation, the military previously reported.

The operation was launched in late March in Gourma, a crossroads region in Mali's central belt that flanks the border with Burkina Faso.

The doctor was killed when his vehicle hit a mine, bringing to 24 the number of French defence force members killed in counter-terrorism operations in the region since 2013.

Some 4,500 French troops are deployed in Mali, Burkina Faso, Niger and Chad to help local forces try to flush out jihadist groups, six years after France helped chase al-Qaeda fundamentalists out of northern Mali.

The Gourma area is a haven for armed groups who hide in the forests along the border with Burkina Faso to the south, including a group suspected of carrying out several cross-border attacks.

Around 700 French troops and 150 Malian troops were deployed in the air and ground operation to try to destroy their bases.

On the other side of the border Burkina Faso had deployed troops "to prevent any attempt by the enemy to escape towards the south of the zone," French military spokesman Patrik Steiger said.

The operation first targeted the Foulsare forest in the southwest of Gao province, where the troops found "a logistical base" containing rocket launchers and other weaponry, the military said.

No jihadists were killed in that offensive, the defence forces said.

The second phase of the operation, which caused the losses on the jihadists' side, targeted several sites including a training camp in the Serma forest.

A pick-up truck, a dozen motorbikes and arms and ammunition, including large amounts of material used to make roadside bombs were seized, the military said.