THE FRENCH army have confirmed its special forces killed a prominent commander with al Qaeda in the Islamic Maghreb (AQIM), the group's north African branch, during an operation in the northern Mali region of Kidal.

France led a military operation to drive Islamist militant groups, including AQIM, out of northern Mali in 2013 after they seized the vast, desert zone a year earlier amid a Tuareg uprising.

However, Islamist militants have intensified operations this year raising regional fears of a spillover in violence, with Malian group Ansar Dine claiming responsibility for a series of recent attacks against U.N. soldiers and Malian army targets.

The French army said it had killed Mohamed Ali Ag Wadossene, identified as a local operations chief for AQIM, during an operation in Mali's Kidal region on Sunday.

Ag Wadossene was among several militants freed by the Malian government as part of a deal in December that saw AQIM release Serge Lazarevic, a French citizen taken hostage by the group three years earlier.

He was believed to have been involved in planning Mr Lazarevic's kidnapping but was later captured and imprisoned in Mali before his release as part of the trade.

"This operation, which destablises the chain of command of one of AQIM's katibas (brigades), once again delivers a heavy blow to terrorist armed groups in the Sahel," the French army said in a statement.

Two other suspected militants were captured in the operation.

Two French special forces soldiers were wounded, though their lives were not in danger and they would soon be evacuated to France, the statement said.

Ansar Dine, which has been allied to AQIM in the past, claimed responsibility for a series of attacks dating back to May.

"God helped Islam's youth to carry out several actions in 2015 against the Malian army," it said in a statement on a website.

Ansar Dine said it was behind attacks on the western Malian town of Nara on June 27 and in Misseni and Fakola in southern Mali, near the border with top cocoa producer Ivory Coast in June and July.

It also said it had attacked UN peacekeepers in Bamako, an apparent reference to a May incident where UN vehicles and a house were targeted.

Ansar Dine has ties to northern separatist groups through its Tuareg renegade commander, Iyad Ag Ghali. But it was excluded from a peace deal last month between Mali's government and northern armed groups that aimed to end decades of Tuareg uprisings.