U.S. President Donald Trump has condemned Russian President Vladimir Putin, the Russian state, and Iran over what he described as a "mindless CHEMICAL attack" by Syrian President Bashar al-Assad's forces that left "many dead, including women and children" in Syria's besieged, rebel-held town of Douma.
"President Putin, Russia and Iran are responsible for backing Animal Assad. Big price... .to pay," Trump wrote in a Twitter post on April 8 after opposition activists and rescuers said dozens of people were killed by a suspected chemical attack on Douma, the last opposition-controlled town in Syria's eastern Ghouta region.
Opposition-linked first responders, so-called Syria Civil Defense emergency workers known as White Helmets, and other activist groups said a helicopter dropped toxic gas inside barrel bombs late on April 7 over Douma, causing people to suffocate and choke.
There was no immediate independent verification of the reports, which Damascus and its ally Moscow dismissed as a "fabrication."
But Trump said Assad's forces were preventing access to Douma by fresh medical teams and international chemical weapons investigators.
"Area of atrocity is in lockdown and encircled by Syrian Army, making it completely inaccessible to outside world," Trump tweeted. "Open area immediately for medical help and verification. Another humanitarian disaster for no reason whatsoever. SICK!"
Russia and Iran have given crucial military and diplomatic backing to Syrian Assad's government throughout Syria's seven-year war, which has killed hundreds of thousands of people and displaced millions.
There were conflicting reports on the number killed by the alleged April 7 chemical attack, with the White Helmets reporting between 40 and 70 dead so far.
The group said victims showed signs of gas poisoning that included pupil dilation and foaming at the mouth.
In a joint statement, the relief organization Syrian American Medical Society and Douma's civil defense service said at least 49 people had died so far as a result of the attack.
The statement said medical centers received more than 500 cases of people suffering breathing difficulties, and that patients gave off a chlorine-like smell.
"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. [Russian] President [Vladimir] Putin, Russia and Iran are responsible for backing Animal Assad. Big price... to pay," he wrote in two separate tweets.
Earlier, the U.S. State Department said Washington was closely monitoring "very disturbing" reports of the possible "horrifying" new use of chemical weapons by Syrian forces.
Russia, with its "unwavering support" for Syria's government, "ultimately bears responsibility" for the alleged attacks, it said in a statement.
"The [Syrian] regime's history of using chemical weapons against its own people is not in dispute," it added.
In a statement, Turkey's Foreign Ministry "strongly" condemned the attack.
"There is strong suspicion [it] was carried out by the regime, whose record on use of chemical weapons is known by the international community," it said.
A joint inquiry by the UN and the Organization for the Prohibition of Chemical Weapons (OPCW) has found that Syrian government forces had used chlorine as a weapon at least three times during the seven-year conflict.
In April 2017, more than 80 people died in a sarin attack on the rebel-held town of Khan Sheikhoun, and a joint inquiry by the UN and the UN-OPCW mission held the Syrian government responsible. Damascus denies using chemical weapons.
Syria's state news agency SANA said the latest reports of a chemical attack were invented by the Jaish al-Islam rebels who remain in control in Douma, which has been under siege from Russian-backed Syrian government forces.
Russian news agency quoted Major-General Yuri Yevtushenko, head of the Russian peace and reconciliation center in Syria, as saying he "decidedly" rejected the allegations.
"The spread of bogus stories about the use of chlorine and other poisonous substances by [Syrian] government forces continues,” Russia's Foreign Ministry later said in a statement.
The ministry said the aim of "such deceitful speculation" was to "shield terrorists" and to try to “justify possible external uses of force."
The British-based Syrian Observatory for Human Rights said government air strikes had killed 70 civilians in Douma since an intense aerial and ground assault was launched on April 6.
The offensive by Syrian government forces and their allies, which involved weeks of intense bombardment, has left more than 1,600 civilians dead and thousands more wounded in eastern Ghouta since February 18, according to the monitor group.