BEIRUT: The US-led coalition in Syria said Monday a patrol had come under attack and engaged in a firefight near a pro-government checkpoint in the country’s northeast. “After receiving safe passage from the pro-regime forces, the patrol came under small arms fire from individuals in the vicinity of the checkpoint,” the coalition said in a statement. “Coalition troops returned fire in self-defense,” it added, saying there were no casualties among its forces. It said it had not conducted an airstrike. The Britain-based Syrian Observatory for Human Rights earlier reported that two Syrian soldiers were killed Monday in a coalition airstrike near the city of Qamishli. It said the strike was carried out after a regime checkpoint refused passage to a coalition patrol. State news agency SANA said one Syrian soldier was killed and two others wounded after they came under fire by coalition forces. Government troops at a checkpoint southeast of Qamishli had blocked the patrol’s passage, SANA said. Coalition forces responded with machine gun fire before two coalition helicopters launched artillery attacks thirty minutes later, it added. Tensions are not unusual in the area, where the web of security responsibilities is complex, but direct clashes between US coalition and regime troops are rare. Kurdish and Russian troops are also deployed in the region.