A fourth French soldier deployed in a military campaign against extremist rebels in Mali was killed on Wednesday.

A fourth French soldier deployed in a military campaign against extremist rebels in Mali was killed on Wednesday, the French government stated.

The soldier, a sergeant from the 68th African Artillery Regiment, was killed during an operation in eastern Mali around 100km from the town of Gao, Reuters said, citing President Francois Hollande’s office.

Dozens of extremist fighters have been killed as French and African forces have fought to drive them out of the northern Malian region, following their control of the country's vast desert north last year.

On Saturday, a paratrooper was killed during an operation to flush out militants from the Ifoghas mountains in northern Mali.

A legionnaire with the 2nd Foreign Parachute Regiment was killed amid heavy clashes on February 19 and a helicopter pilot died at the very start of the operation.