US special forces have carried out a counter-terrorism raid in opposition-held north-western Syria, close to the Turkish border, the Pentagon has said.
A spokesman said the mission was successful and that there were no US casualties, but gave no other details.
The White Helmets rescue service reported that at least 13 people, including six children and four women, were killed in the town of Atmeh.
The area is believed to be home to foreign jihadists linked to al-Qaeda.
Residents of Atmeh said several helicopters landed there around midnight on Thursday (22:00 GMT on Wednesday) and that they heard gunfire and shelling for two hours.
Photographs posted on social media afterwards showed destroyed buildings
The Syrian Observatory for Human Rights, a UK-based monitoring group, said the US operation was the largest in north-west Syria since Islamic State (IS) leader Abu Bakr al-Baghdadi died in a special forces raid in October 2019.