MANBIJ, Syria (AP) — Residents of the small alley where an explosion killed two members of the U.S.-led coalition this week were fixing their windows and the fronts of their homes on Saturday. Shards of glass still littered the dirt road and metal shutters were twisted out of shape.

The explosion Thursday was the first to hit the U.S.-led coalition deployed here months after the town was liberated from Islamic State militants in 2016. An American and a Briton were killed, and a number of local security members were injured. The improvised explosive device went off during an operation against a member of the Islamic State group in this mixed Arab and Kurdish town, the U.S.-led Coalition said Saturday.

"Coalition forces, in an advise, assist and accompany capacity with our partners, were conducting a mission to kill or capture a known (IS) member when they were struck by an improvised explosive device," the coalition said in a statement to The Associated Press.

Residents described a large blast. A local security member on the scene, who spoke on condition of anonymity because he was not authorized to speak to the press, said there was gunfire before the explosion went off. Locals speculated the explosion was caused by a suicide bomber, judging by the extent of the damage to the alley and the bodies.

"Half an hour after the explosion, the choppers were in the air," resident Mohammed Eid said, adding the explosion just before midnight woke him up.

His family, which lives in the building opposite where the explosion happened, was fixing windows in the first floor Saturday.

Local authorities said a joint investigation was ongoing. It follows what appeared to be rare joint raid in Manbij against suspected IS cells.

The town has served as a model of stabilization in post-IS areas in northern Syria.

But in recent weeks, Manbij has seen an assassination attempt against a senior Kurdish official on the highway outside the town and a number of small explosions. Authorities imposed a curfew after 11 p.m., and in recent days barred motorcycles from moving around the town after sunset.

It is not clear who was behind the attacks. Officials express concern about IS attempting to re-emerge and accused Turkey and the Syrian government of seeking to destabilize the town.

Turkey has threatened to move on Manbij to expel the U.S-backed Kurdish militia in control.

U.S. troops have increased their visibility in Manbij and around the front line that separates the town from Turkey-backed fighters.