KABUL, Afghanistan — Dozens of civilians and militia forces were killed in northern Afghanistan in what officials on Sunday described as an attack by Taliban fighters teamed up with a commander claiming allegiance to the Islamic State. If true, the open cooperation between the militant groups, which have sometimes fought turf battles in the past, could be further trouble for the struggling Afghan government.
Sayad district, in northern Sar-e-Pul province, had put up a fierce defense over the past two years against attacks by insurgents as other parts of the province seemed to be buckling under Taliban pressure. Several local officials say the Taliban joined forces with Sher Mohammed Ghazanfar, a local commander claiming allegiance to the Islamic State, to overrun the Mirza Olang area. Then he turned to blocking local militiamen, as well as civilians, from fleeing.