An alliance of U.S.-backed militias said it had begun a new phase of its campaign against the Islamic State-held city of Raqqa on Saturday and aimed to complete its encirclement.
The Syrian Democratic Forces (SDF) said in a statement the action was being undertaken with "increasing support from the (U.S.-led) international coalition forces through guaranteeing air cover for our forces' advances, or via the help provided by their special teams to our forces on the battle ground".