A bus with Syrian rebels and their families aboard leaves Wafideen camp in Douma, Syria, on April 9, 2018. Omar Sanadiki / AFP
A bus with Syrian rebels and their families aboard leaves Wafideen camp in Douma, Syria, on April 9, 2018. Omar Sanadiki / AFP

France says it will take action if 'red line' on chemical arms is crossed by Syria