An Afghan official says a roadside bomb killed at least nine security forces during an ongoing operation in the northern Balkh province.

Munir Ahmad Farhad, spokesman for the provincial governor, said Sunday that several other forces were wounded the night before in the Chimtal district, where they are battling Taliban insurgents. He says five insurgents have been killed and dozens wounded.

Afghan forces have struggled to combat the Taliban since the U.S. and NATO formally concluded their combat mission more than two years ago. The Taliban have seized a number of districts across the country, and the fighting is expected to intensify as warmer weather sets in.