GENEVA - Syria's major opposition armed groups will issue a statement in the coming hours backing a cessation of hostilities from sundown today, a source within the opposition told Reuters on Monday. 'The decision is taken,' the opposition source said, speaking on condition of anonymity. 'In the next few hours there will be a statement where we state that, but there will be a lot of harsh reservations and observations regarding the whole package. But as a final takeaway, we do agree.'