A suspected chemical attack against the Damascus suburb of Irbin left two civilians dead and seven injured on Thursday, a local hospital reported.

According to a statement issued by the Surgical Hospital of Irbin, seven kilometers (4.3 miles) northeast of the capital, nine patients arrived at the hospital at noon suffering from symptoms of an “unknown gas poisoning.” Two of the patients were unconscious at the time of their arrival, and exhibiting severe symptoms including a bloating of the face and redness in the eyes.

The patients were hysterical upon regaining consciousness, suffering lack of sensation in the limbs, the statement said.

Five other patients suffered from headaches and shortness of breath, with no signs of pulmonary disease. The two fatalities displayed redness in the conjunctiva (the inner part of the eyelid), the report continued.

The Times of Israel could not independently confirm the report, but a short video posted to YouTube Thursday by a group called “the unified media bureau of Irbin” featured a young man gasping for air on a hospital bed as a medical team pours water over him and listens to his chest.

Under an agreement reached between the Assad regime and the United Nations last September, Syria is supposed to eliminate its chemical stockpiles by the end of June. But UN Secretary General Ban Ki-moon announced on May 29 that Syria would not meet its deadline, with an estimated 7.5 percent of the substances still in the country.

A member of the Syrian opposition told The Times of Israel last week that the regime has been transporting chemical weapons to a remote mountainous area north of Hama, in central Syria.

“According to our information, this is not the first time that chemical weapons are moved from place to place,” the opposition member said. “We believe the regime has hidden a large amount of VX (nerve agent) which is extremely toxic.”

He estimated that the Assad regime may still be in possession of at least 20% of its chemical stockpiles. The Israeli government agrees that Assad still holds “considerably more” than the 7.5% he proclaims to have.

A senior IDF officer told The Times of Israel last month that the Assad regime has used chemical weapons at least 30 times since joining the Chemical Weapons Convention last year, with civilians killed in every attack. Human Rights Watch said it had “strong evidence” that the regime had dropped chlorine bombs from helicopters over rebel-held towns at least three times in mid-April, killing at least 11 people and wounding as many as 500.