KONNA, Mali — French special forces took control of the airport in the Islamic rebel stronghold of Gao, the French government said Saturday, meeting “serious resistance” from militants even as they pressed northward.

Gao is one of three main northern cities in Mali that has been under rebel control for months, and the capture of the main strategic points in Gao represents the biggest prize yet in the battle to retake the northern half of the country.

French airstrikes have been pounding the city since France joined the fight at Mali’s request on Jan. 11. French troops also took control of a bridge over the Niger River on Saturday, and the capture of the airport allowed a company of French soldiers to be airlifted in on Saturday afternoon, according to Col. Thierry Burkhard, the French military spokesman.

Another French company was on the road to Gao from Sévaré on Saturday night, and Malian and other African forces had begun to arrive, he said.