Syrian force a 'few weeks' from Raqqa, U.S. Marines deploy

By Tom PerryBEIRUT (Reuters) - U.S.-backed Syrian forces said on Thursday they were closing in on Islamic State-held Raqqa and expected to reach the city outskirts in a few weeks, as a U.S. Marines artillery unit deployed to help the campaign.The Syrian Democratic Forces (SDF), a militia alliance including the Kurdish YPG, is the main U.S. partner in the war against Islamic State in Syria.Since November it has been working with the U.S.-led coalition to encircle Raqqa.