French forces have killed more than 150 Islamist rebels since mid-February in fighting for Mali's northeastern Ametettai valley and around the city of Gao, the military said on Thursday.
French forces, who have taken control of the Ametettai valley in recent days, were on Thursday carrying out operations to sweep the valley and other areas of the Ifoghas mountains where Islamist militants fled after being driven out of Mali's northern cities.
French military spokesman Colonel Thierry Burkhard said militants with Al-Qaeda in the Islamic Maghreb (AQIM) had "set up in this area and wanted to stay in the long-term".
He said it was "likely that some terrorists managed to escape" during the operations.
Some 4,000 French troops are in Mali working with West African forces and Malian soldiers to hunt down the rebels after a French-led intervention launched in mid-January drove them from areas of northern Mali they seized last year.