(Syrian Civil Defense White Helmets | The Associated Press) This image made from video released by the Syrian Civil Defense White Helmets, which has been authenticated based on its contents and other AP reporting, shows a medical worker giving toddlers oxygen through respirators following an alleged poison gas attack in the opposition-held town of Douma, in eastern Ghouta, near Damascus, Syria, Sunday, April 8, 2018. Syrian opposition activists and rescuers said Sunday that a poison gas attack on a rebel-held town near the capital. The Syrian government denied the allegations, which could not be independently verified.