More than 30 fighters of Al Rahman Corps reportedly affected by chlorine gas attack

Over 30 opposition fighters have been affected as Syrian regime conducted a chlorine gas attack in Eastern Ghouta region of capital Damascus, an armed opposition group claimed Saturday.

"More than 30 suffocation cases were reported after the regime targeted the points of Al Rahman Legion's fighters and used poisonous chlorine gas, which is prohibited by international law, on Ein Tarma Front following the failure of regime forces to storm the area for 13 days in row,” the Al Rahman Corps (Faylaq Al Rahman) said on its Twitter account.

"The gas attack has been conducted by artillery fire," Waiel Olwan, spokesman of the group, told Anadolu Agency.

He said, as the regime forces attempted to advance from Zamalka area, south of Ein Tarma, "We have responded to the attack of the regime forces and killed 30 of their soldiers. So, they resorted to [using] chemical weapons."

Olwan also posted on his Twitter account, saying "a great loss incurred" by the regime.

Separately, Assad regime forces on Saturday afternoon launched an artillery attack in west-central Hama province on civil defense center of the White Helmets -- a volunteer rescue group established in 2014 operating in Syria's opposition-held areas, the group announced on its Twitter account.

The building was largely damaged as two rescue vehicles were totally destroyed, according to the civil defense group.

In early May, Russia, Turkey and Iran agreed in the Kazakh capital, Astana, to establish "de-escalation zones" in war-torn Syria.

According to the agreement, the zones would cover the city of Idlib and certain parts of Latakia, Homs, Aleppo and Hama as well as Damascus, Eastern Ghouta, Daraa and Quneitra.

Syria has been locked in civil war since March 2011, when the Assad regime cracked down on pro-democracy protests with unexpected ferocity.

According to UN's special envoy for Syria, Staffan de Mistura, around 400,000 people have died in the conflict while half the population has been driven from their homes.

Syrian regime used chlorine in E. Ghouta: Opposition ile ilgili görsel sonucu

AA