An al - Qaeda - linked militant group and the so - called Free Syrian Army have agreed on ceasefire in the northern Syrian town of Azaz after days of clashes.The truce between the al-Qaeda-linked Islamic State of Iraq and the Levant (ISIS) and the Western-backed FSA was brokered by Liwa al-Tawhid, a powerful militant brigade loyal to the FSA. The two militant groups have agreed to exchange prisoners and hand back property. It is not clear whether the truce will have an impact on clashes between the two groups elsewhere in the country. They also agreed that any future problems that might emerge be dealt with by an arbitration committee. Militants from ISIS captured Azaz, located on the border with Turkey, from the Northern Storm brigade, which is loyal to the FSA, on Wednesday. At least five militants from FSA were killed during the hours-long fighting. Fighting in Azaz began after an injured militant --either from ISIS or from an allied group -- was taken to a field clinic in the town where he was filmed as part of a fundraising exercise. The wounded militant demanded the film, and called some of his friends to come and help him which ended up with ISIS launching a full attack on the town. ISIS militants took scores of civilians hostage and arrested many opposition activists and citizen-journalists after capturing the town. Over 100 FSA militants are also reported to have been detained by ISIS. Following the clashes in Azaz, Turkey closed its border crossing in the region for "security reasons". "The Oncupinar border gate has been closed due to activity and uncertainty on the Syrian side of the border," a Turkish official said on Thursday, adding that it was a temporary measure.