Fifteen Islamist fighters have been killed in recent days in the northern Mali region of Gao, the French army said Tuesday, announcing the seizure of a large cache of arms and ammunition. The claim came two weeks after France said more than 150 Islamist rebels had been killed since the middle of February in Mali. French losses in the intervention have been limited to five casualties. The French soldiers came under sporadic heavy- and medium-range fire in the area of Djebok, east of Gao, the joint staff said, adding that they "neutralised 15 terrorists" since Thursday. They found eight vehicles mounted with anti-aircraft guns, landmines and a large horde of weapons and ammunition. France has more than 4,000 troops on the ground in Mali, of whom about 1,200 are currently deployed in the northeast, carrying out clean-up operations after driving out most of the Islamist rebels from the area. There are still pockets of resistance in areas such as Gao, which have witnessed stray attacks and suicide bombings since the Islamists fled. The French troops in the region are backed up by African forces. Soldiers from Chad, whose experience and training has made them key in the French-led offensive, have also suffered casualties with at least 26 deaths. Paris deployed forces in Mali on January 11 to help stop Al-Qaeda linked fighters who had controlled northern Mali since April 2012 from moving southward and threatening the capital Bamako.