A U.S.-led coalition patrol in Syria’s disputed northern Manbij was attacked by an Islamic State suicide bomber on Wednesday, claiming the life of at least two American soldiers, according to unconfirmed local reports.

Witness said the attacker had targeted the patrol and the militia group claimed on Facebook there was preliminary information of injuries.

Hawar News, which has links to the Kurdish YPG, said two American soldiers had died while another two were wounded. Around 350 members of the US-led coalition — mostly American troops — are stationed around Manbij.

Video from the scene showed a coalition helicopter landing at the scene of the blast to take the injured away. The attack comes as the U.S. has begun the process of withdrawing from Syria.

U.K.-based Syrian Observatory for Human Rights and the Kurdish-led Manbij Military Council, which runs the town, said the attack and subsequent blast occurred near a local restaurant.

No confirmation of the attack or possible American casualties has been made by U.S. military sources, although some sources indicate the toll could be higher than initially thought:

RIP: Four US soldiers have reportedly been killed in an ISIS-claimed suicide bombing on a busy restaurant in Manbij. The blast left a total of 16 dead – Reuters — Breaking911 (@Breaking911) January 16, 2019

“The President has been fully briefed and we will continue to monitor the ongoing situation in Syria. For any specific questions please contact the Department of Defense,” White House press secretary Sarah Huckabee Sanders said in confirming the reports of the attack.

U.S. President Donald Trump announced on December 19 that he was withdrawing all 2,000 American troops from the conflict-wracked Middle Eastern country. That process is now underway.