The Syrian White Helmets voluntary rescue group wrote on Twitter on Sunday that a helicopter had dropped a barrel bomb filled with chemicals on the rebel-held city of Douma late on Saturday, killing at least 40 people and injuring hundreds. 

"Entire families in shelters gassed to death in Douma, eastern Ghouta, hiding in their cellars, suffocated from the poisonous gas bringing the initial death toll to more than 40," the organization said.

The Union of Medical Care and Relief Organizations (UOSSM) meanwhile said that the death toll was expected to rise to "well over 100." UOSSM also reported that the attack had injured over 500 in eastern Ghouta.

After the alleged attack, Russian-backed government forces have reportedly pressed ahead with their military offensive to retake what is the last opposition pocket near the capital, Damascus. The Britain-based Syrian Observatory for Human Rights (SOHR) said fresh airstrikes were continuing to hit parts of eastern Ghouta on Sunday, despite reports saying the fighters had struck a ceasefire deal with Syrian regime ally Russia.

The SOHR is monitoring the Syrian conflict through a network of activists on the ground.

Mixed numbers

The medical relief organization Syrian American Medical Society (SAMS) meanwhile also said that a chlorine bomb hit Douma hospital, killing six people, and that a second attack with "mixed agents" including nerve agents had hit a building nearby.

Basel Termanini, the US-based vice president of SAMS, told the news agency Reuters the total death toll in the chemical attacks was 35.

Damuscus, Russia deny guilt

The official Syrian news agency SANA rejected the reports.

"Some media outlets, known for their support to the terrorists, claimed that the army used chemical weapons in the city of Douma during its military operations in response to the attacks carried out by the terrorist organization on several Damascus neighborhoods and its surroundings," SANA said.

Russia has also rejected the claims that Syrian government forces used chemical weapons in the Douma assault.

The chairman of the international affairs committee of Russia's upper house of parliament, Konstantin Kosachev, said on Sunday that the reports were bogus. He added that Washington was attempting to "impede the offensive by Syrian government forces" by claiming their use of such weapons.

SOHR director Rami Abdulrahman said he could not confirm if chemical weapons had been used.

But SOHR did confirm that 80 civilians were killed on Saturday in Douma, having suffocated in the smoke caused by dropping conventional weapons.

‘Russia should be blamed'

The US State Department said on Saturday evening it was monitoring the situation and that Russia should be blamed if chemicals had been used.

"The regime's history of using chemical weapons against its own people in not in dispute," a State Department official said in a statement, referring to the government of Syrian President Bashar al-Assad.

"Russia ultimately bears responsibility for the brutal targeting of countless Syrians with chemical weapons," the statement said.

In March, the US warned at the UN that it would react to any chemical weapon attacks in Syria.

Russian Ambassador Vassily Nebenzia said the Russian-backed operation in eastern Ghouta was part of a counterterrorism mission.

jbh/es (dpa, Reuters)

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