Iraqi militias, backed by Iran, attacked a US base located in the Al-Omar oil field in eastern Syria, the Syrian Observatory for Human Rights (OSDH) said.
A base in Deir ez-Zor province was the target of a drone attack on Thursday, drawing air defense fire, with no casualties or injuries reported, London-based OSDH said.
Also on Thursday, a group of American helicopters crossed at low altitude into the airspace of the Euphrates River, which divides the territory controlled by these militias, after which explosions were heard in the city of Abu Kamal, on the border with Syria. Iraq, sources on the ground told the NGO.