'Big price to pay' - Trump threatens to retaliate on Syria for chemical weapons attack
Scores feared dead in alleged Syria chemical attack as US demands international response
US President Donald Trump has said Syrian President Bashar al-Assad will have a "big price to pay" for launching a deadly chemical weapons attack on civilians, and blamed Iran and Russian President Vladimir Putin for backing "animal Assad."
President Trump condemned the "mindless chemical attack" in Syria that has killed women and children.
But the president offered no evidence to support the claim by Syrian opposition activists and rescuers that poison gas was used.
Syrian President Bashar Assad's government is denying the allegations of such an attack on a rebel-held town near Damascus, the capital.
President Trump said in a tweet on Sunday that the "area of atrocity is in lockdown and encircled by Syrian Army, making it completely inaccessible to outside world."
He said Russian President Vladimir Putin and Iran - influential Syrian backers - "are responsible for backing Animal Assad".
"Many dead, including women and children, in mindless CHEMICAL attack in Syria. Area of atrocity is in lockdown and encircled by Syrian Army, making it completely inaccessible to outside world," Trump wrote on Twitter.
"President Putin, Russia and Iran are responsible for backing Animal Assad. Big price to pay," he wrote.
He is now calling for the area to be opened immediately for medical help and verification.
At least 49 people were killed in the attack, according to a medical relief organisation.
Douma's civil devence service said medical centres were dealing with more than 500 cases of people frothing from the mouth, suffering breathing difficulties and smelling of chlorine.
"Another humanitarian disaster for no reason whatsoever. Sick," he said.
With additional reporting from Reuters and Press Association