"Washington: US intelligence agencies believe Syria's government has likely used chemical weapons on a small scale, the White House said on Thursday, but added that President Barack Obama needed "credible and corroborated" facts before acting on that assessment. The disclosure of the assessment, which Defense Secretary Chuck Hagel said was made within the past 24 hours and the White House said was based in part on physiological samples, triggered immediate calls for US action by members of Congress who advocate deeper US involvement."

