Syria conflict: Rival anti-IS groups clash near Raqqa
Fighting has erupted between units from the Kurdish-Arab SDF alliance and Turkish-backed rebels in Syria.
Over the weekend the US deployed special forces near Raqqa, the stronghold of the Islamic State jihadist group, in an attempt to end the clashes.
US Secretary of State Rex Tillerson is to host talks with coalition members on 22 March ahead of an expected assault on Raqqa.