A suicide car bomb attack on a military convoy in northeastern Syria Monday killed five members of the Syrian Democratic Forces (SDF) accompanying U.S.-led coalition troops, a monitor said.

The Syrian Observatory for Human Rights said five fighters from the People's Protection Units (YPG)-dominated SDF were killed in the attack, which occurred on a road in Al-Hasakah province.

Local media outlets said the blast was a suicide bombing that targeted a checkpoint near the town of Shaddadeh.

The head of the Britain-based Observatory, Rami Abdel Rahman, said the attacker's vehicle hit an SDF vehicle.

U.S. military Col. Sean Ryan said there were no casualties among the U.S.-led coalition members.

Deash terrorist group claimed the attack in a statement carried by its Aamaq news agency.

Shaddadeh lies to the south of Al-Hasakah, capital of the eponymous province, which has been relatively spared by the war that erupted in Syria nearly eight years ago.

The attack, on which there was no immediate comment from the coalition, came less than a week after another attack on the U.S.-led force and its local partners in the strategic city of Manbij.

Four Americans -- two members of the military, a Pentagon civilian and a contractor -- were killed in a blast that targeted a restaurant in the city center on January 16.

The Manbij attack cost Washington its worst combat losses since it deployed in the war-torn country to combat Daesh.

Ten civilians were also killed in the attack, as well as five fighters from the local force that was patrolling the city alongside the coalition.