A week-old Syrian ceasefire brokered by the United States and Russia is in deep trouble on Monday after a rebel official said they're planning for a full resumption of fighting.<br />The ceasefire came was interrupted over the weekend when Russia said jets from the U.S.-led coalition against Islamic State killed more than 60 Syrian soldiers in eastern Syria.<br />The agreement is the second ceasefire negotiated by Washington and Moscow this year in the hope of advancing a political end to a war now in its sixth year, which has killed hundreds of thousands of people.<br />While it has led to a significant reduction in fighting over the past week, violence has been increasing in recent days.<br />A planned delivery of humanitarian aid to besieged rebel-held districts of eastern Aleppo - one of the first steps in the deal - has been repeatedly postponed.
