French and Malian soldiers appeared to push farther north into militant-held territory on Friday, closing in on the eastern city of Gao, the stronghold of one of the several Islamist groups that have captured northern Mali.

Residents of Hombori told news agencies that they had seen French and Malian soldiers in the town, which sits 155 miles southwest of Gao, one of the three large cities in northern Mali under militant control.

An Islamist group blew up a bridge in another small town, Ansongo, near the border with Niger, according to residents and aid workers in the area, in an apparent attempt to prevent soldiers from gaining ground in that area.

French officials have been wary of disclosing the precise movements of their 2,500 troops on the ground in Mali, and on Friday a French military spokesman, Col. Thierry Burkhard, declined to confirm or deny that Malian or French forces had taken Hombori, where two Frenchmen were kidnapped in 2011. But he said that French aerial strikes were continuing against militants farther north.