About 100 Islamic militants ambushed an army camp in western Niger and killed at least 71 soldiers, a military spokesman said late Wednesday, in the deadliest attack on the West African country’s forces in years.

The attack comes amid a surge of assaults on army camps in the Sahel region, which have allowed jihadists to amass weapons and vehicles for their arsenal. Mali, a neighboring West African country, has seen such an increase in ambushes on its army that it has closed some of its most remote and vulnerable army outposts.

Col. Boukar Hassan, a spokesman for Niger’s army, read the death toll announcement on state television Wednesday night and said a dozen other people had been wounded after the ambush overnight.

Earlier in the evening, a tweet sent from the account of President Mahamadou Issoufou of Niger announced that he was returning early from an overseas trip in Egypt, following developments near Niger’s border with Mali.