Kurdish and Arab fighters say they have liberated the north Syrian town of Manbij from so-called Islamic State, cutting off its route to Europe.
The coalition of militias fought 73 days to drive out IS and say they freed 2,000 civilians being used as human shields on the final day.
IS captured Manbij, close to the Turkish border, two years ago. Roads to Syria's embattled second city, Aleppo, and to the IS capital, Raqqa, pass through the town.
"After the liberation of Manbij, IS members won't be able to freely travel to and from Europe anymore," said Syrian Kurdish leader Salih Muslim.
The Syrian Democratic Forces (SDF) coalition includes the powerful Kurdish YPG militia. They were backed in their campaign against IS by US-led air strikes on IS positions.
Responding to reports of the human shields, EU foreign affairs chief Federica Mogherini said in a statement that IS continued to "pose a threat to the people of Syria, Iraq, the region as well as to Europe and beyond".
"The recent military advances against Da'esh [IS] by the Global Coalition together with the Syrian Democratic Forces in North West Syria are welcome and the EU will continue to commit its efforts, as part of the Coalition, to its non-military fields of activity," she added.
The roads through Manbij had become crucial to the group's ability to move fighters, weapons and supplies in and out of Syria.
According to the Syrian Observatory for Human Rights, which monitors the conflict from the UK, around 500 cars left Manbij carrying IS members and civilians.
They were heading north-east towards Jarablus, a town under IS control on the Turkish border.