WARNING-STORY CONTAINS GRAPHIC IMAGES<br/> <br />STORY: The U.S. is laying out its case for action in Syria.<br/> <br />Secretary of State John Kerry says the administration has enough evidence to blame President Bashar al-Assad for last week's alleged chemical weapons attack.<br/> <br />(SOUNDBITE) (English) U.S. SECRETARY OF STATE JOHN KERRY SAYING:<br/> <br />"We know rockets came only from regime-controlled areas and went only to opposition-controlled or contested neighborhoods."<br/> <br />His declaration comes as a new White House report says the attack killed more than 1,400 Syrian civilians, including more than 400 children.<br/> <br />The report was based in part on intercepted communications among senior Syrian officials.<br/> <br />The attack was revealed in an online video that Reuters cannot independently verify.<br/> <br />The video appeared to show men, women and children panicking in streets outside Damascus, following by victims struggling to breathe on the floors of a medical clinic.<br/> <br />The U.S. is leadi
