French forces advance in Mali against radical Islamists, face 'acts of harassment' French forces took control of the airport and a key bridge in the radical Islamist stronghold of Gao under cover of darkness early Saturday, making a significant inroad into territory held by the Al Qaeda-linked extremists. The move comes just two weeks after France launched its military offensive to rout the Islamists from power in northern Mali. It isn't clear what kind of resistance they will face in coming days French and Malian forces came under fire in the morning and continued to face sporadic "acts of harassment," in the afternoon, said Col. Thierry Burkhard, a French military spokesman in Paris. He had no immediate estimate on casualties. The Islamists first seized control of Gao and two other northern provincial capitals - Timbuktu and Kidal - last April during the chaotic aftermath of a coup in the distant capital. French Defense Minister Jean-Yves Le Drian announced in a statement from his ministry Saturday that jihadist fighters who encountered the advancing French and Malian troops "saw their means of transport and their logistics sites. Before the joint air-land operations overnight, French forces carried out "an important phase of airstrikes" around Gao and Timbuktu, with nearly 30 bombs fired from fighter jets over the previous two days, the military said. More French and African troops and equipment were being sent to Gao, the French Defense Ministry said. Troops from Chad and Niger "should arrive in the Gao area very soon," it added. Elsewhere in Mali, French and Malian troops supported by a tactical air group carried out a nighttime "reconnaissance offensive" toward Lere, "where several terrorist elements were noticed a few days earlier," the military said. Two Rafale jets have been added to the campaign, bringing France's total deployment to 12 fighter jets as part of the code-named Operation Serval in Mali, the military said. Nouhoum Maiga, a deputy mayor in Gao, confirmed Saturday that the French had come by land and air late Friday. Gao has been under the control of the Al Qaeda-linked Movement for Oneness and Jihad for months. On Friday in a show of might, the Islamist radicals destroyed a bridge near the Niger border with explosives, showing that the extremists still remain a nimble and daunting enemy. Since France began its military operation two weeks ago with a barrage of airstrikes followed by a land assault, the Islamists have retreated from three cities in central Mali: Diabaly, Konna and Douentza. The Islamists, though, have maintained control of the majority of the territory in Mali's north, most importantly the cities of Gao, Kidal and Timbuktu. The announcement that Gao's airport had been taken marked the first official confirmation that French and Malian forces had reached the city. Previously the closest they had been was Hombori, a town some 155 miles away. The French currently have about 2,500 troops in the country and have said that they will stay as long as needed in Mali, a former French colony. However, they have called for African nations to take the lead in fortifying the Malian army's efforts. There are currently some 1,750 troops from neighboring African countries, including Togo, Nigeria, Burkina Faso, Benin, Senegal, Niger and Chad.