A suicide bomb attack at a busy marketplace in the northern Syrian city of Manbij caused an unknown number of casualties, with American military personnel among those killed and injured, according to reports.

ANHA news agency shared video of the aftermath of the Wednesday, January 16 attack, showing a burned building and damage to nearby vehicles.

In an explosion near a restaurant in Manbij’s busy market death and injuries reported. Unconfirmed reports about 2 American soldier also killed in the explosion @hawarnews #TwitterKurds pic.twitter.com/GNWevN5clh — Mutlu Civiroglu (@mutludc) January 16, 2019

Two U.S. military personnel were killed in the explosion, Central Command said.

“Two U.S. servicemembers, one Department of Defense civilian and one contractor supporting DoD were killed and three servicemembers were injured while conducting a local engagement in Manbij,” CENTCOM said in a press release.

Their names are being withheld for 24 hours in accordance with Defense Department policy.

“Initial reports indicate an explosion caused the casualties, and the incident is under investigation,” the release added.

Purported CCTV footage of the incident showed an explosion at a building on a busy street. The timestamp on the graphic video was 12:38 p.m. (1038 GMT) on a Wednesday in 2019.

The explosion occurred in front of the Qasr al-Amra’ restaurant on the Sindis street, ANF reported, adding that as many as 11 people were killed and 20 wounded. Other reports had a higher toll.

Photographs and video posted after the incident appeared to show a Coalition military helicopter in the area.

“U.S. service members were killed during an explosion while conducting a routine patrol in Syria today,” the U.S.-led Coalition against Islamic State tweeted, adding that information was still being gathered.

The Coalition earlier acknowledged reports of the explosion and said that its forces were on patrol.

“CJTF-OIR is aware of open source reports regarding an explosion in Syria,” Coalition spokesperson U.S. Army Colonel Sean Ryan told The Defense Post by email.

“Coalition forces conducted a routine patrol in Syria today. We are still gathering information and will share additional details at a later time,” Ryan said.

Coalition forces have previously been attacked in the city. In March 2018, one U.S. Army special operator and one British special forces member were killed in an IED explosion in Manbji. Five other Coalition personnel were injured in that attack.

ISIS claims responsibility

Islamic State’s propaganda arm Amaq said “a martyrdom attack with an improvised explosive device hit an international coalition patrol,” an apparent claim of responsibility for the attack.

An ISIS statement later identified the suicide bomber as Abu Yasin al-Shami. It said nine “crusaders” were killed or injured in the explosion near Qasr Al-Omara restaurant, along with “a number of their associates.”

Manbij was captured from Islamic State on August 12, 2016 by the U.S.-backed Syrian Democratic Forces after a 75-day battle, later named “Operation Martyr and Commander Faysal Abu Layla” after the SDF commander.

Fighters from the People’s Protection Units (YPG) and Women’s Protection Units (YPJ) made up the bulk of those deployed in the operation, and the YPG said it handed its points of control west of the Euphrates river to the Manbij Military Council, which has been in control of the town since.

U.S. and Turkish personnel have been conducting joint patrols outside Manbij since November, and Russian military police acting in support of the Syrian military began patrols in the area on January 8.

With reporting from AFP. This is a developing story.