A medical worker giving toddlers oxygen through respirators following an alleged poison gas attack in the opposition-held town of Douma, Syria. Picture: Syrian Civil Defense White Helmets via AP

Geneva - The World Health Organisation condemned a suspected chemical weapons attack in Douma, Syria last weekend, in which it said an estimated 500 patients went to health facilities with "signs and symptoms consistent with exposure to toxic chemicals".

"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," Peter Salama, WHO deputy director-general for emergency preparedness and response, said in a statement issued in Geneva.

UN aid agencies do not have access to most of the enclave of eastern Ghouta, including Douma, where the alleged attack occurred. The Syrian government has denied responsibility.

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