April 11 (UPI) -- The World Health Organization said Wednesday it's demanding "unhindered access" to Douma, Syria, to check on hundreds of people who may have been affected by a chemical attack last weekend.
Syria denies using chemical weapons in the attack that killed as many as 75 people, after officials said at least one government-allied helicopter dropped a barrel bomb of chemicals that left civilians, including children, suffocating.
WHO wants access to the victims of the attack, which sent about 500 to health facilities with signs and symptoms consistent with toxic chemical exposure -- including severe irritation of mucous membranes, respiratory failure and disruption to central nervous systems.
More than 70 people sheltering in basements died, with 43 of the deaths related to symptoms consistent with exposure to highly toxic chemicals. Also affected by the attacks are two health facilities, according to the WHO.
Wednesday's statement by WHO officials reminds parties to the conflict the use of chemical weapons is illegal under international law.
"We should all be outraged at these horrific reports and images from Douma," said WHO Deputy Director Dr. Peter Salama. "WHO demands immediate unhindered access to the area to provide care to those affected, to assess the health impacts and to deliver a comprehensive public health response."
WHO is coordinating help for people displaced by the attack in the Eastern Ghouta suburb and officials said the organization is ready assist with medical care as soon as access is granted.
International chemical watchdog Organization for the Prohibition of Chemical Weapons said Tuesday it asked Syria to make arrangements so the group could send a team there for a fact-finding mission.