The spokesman for the U.S.-led coalition Col. Sean Ryan said their partner forces acted in "self-defense" after coming under fire from the western side of the Euphrates River. U.S.-led coalition forces, with their local Kurdish-led partners, are battling the remnants of Islamic State group on the eastern banks of the Euphrates, while government troops and allied forces are now positioned on the other side after dislodging IS from there.
The incident highlights the risks of operating in close proximity with rival forces in the crowded area where IS militants are making their last stand. An unnamed Syrian military official told state news agency SANA that the coalition's attack took place late Saturday on government positons in Sukkariyah, west of Boukamal town. It was followed by a foiled incursion by IS militants, he added, accusing the U.S. of aiding the militants. Damascus often accuses Washington of aiding "terrorists" to destabilize the government.
The Britain-based Syrian Observatory for Human Rights monitoring group said militants, holed up in a small area on the Euphrates' eastern bank, launched an attack against government forces and allied Iranian-backed troops in an apparent attempt to clear an escape route westward toward the desert. The militants also fired at government troops from their position, said the Observatory.
The Observatory said the IS attacks lasted for hours and left at least 11 militants, including three suicide bombers, dead. Since the U.S. announced in December that it's withdrawing troops from Syria, Syrian government troops have beefed up their presence on the western banks of Euphrates. The timetable for the U.S. withdrawal is not yet clear.
The U.S.-led coalition and local Kurdish-led partners have been battling IS militants on the eastern banks of the river since September. The militants are now holding out in two farm areas along the river about four square kilometers (1.5 square miles) in size. Thousands of civilians have fled the fighting but many are still believed to be trapped with the remaining militants.
Associated Press writer Albert Aji in Damascus, Syria contributed to this report.