(AFP) BEIRUT, Lebanon — A child died and at least 13 other people suffered breathing difficulties after a suspected chemical attack on a besieged Syrian rebel enclave Sunday, a medic and a monitor said.

The Britain-based Syrian Observatory for Human Rights said 14 civilians had suffered breathing difficulties after a regime warplane struck the village of Al-Shifuniyah in the Eastern Ghouta region.

One child died and a woman was in a critical condition, said Rami Abdel Rahman, head of the Observatory which relies on multiple sources on the ground in Syria for its reports.

Yaqub, a doctor who treated those affected, told AFP he suspected “chemical weapons, probably a chlorine gas attack.”

He said a three-year-old had died of asphyxiation.

“Most of the patients have chlorine odor from their clothes and their skin. Many have dyspnea [labored breathing] and skin and eye irritations,” he said in English.

Rebels accused Damascus of using chlorine gas, but Moscow, a staunch ally of Syrian President Bashar al-Assad’s regime, accused his opponents of using “toxic substances” to make it appear that they had been deployed by regime forces.

Damascus, which has repeatedly denied using chemical weapons, has been accused of several chlorine gas attacks in recent weeks, including two in January in eastern Ghouta, a rebel stronghold on the edge of the capital which has been battered by regime strikes since mid-February.

Recent reports of regime chemical attacks have prompted France to warn of strikes in Syria, after similar remarks by an official in Washington.

Regime ally Russia accused rebels of carrying out the attack.

They “prepare a provocation, using of toxic substances to accuse government forces of using chemical weapons against the civilian population,” the defense ministry said.

The Observatory reported 21 cases of suffocation in eastern Ghouta on 22 January. Residents and medical sources said they suspected a chlorine attack.

A similar attack targeted the outskirts of Douma on January 13, the monitor said.

The Syrian regime has denied possessing chemical weapons.

The reports came a day after the United Nations demanded a ceasefire to end one of the most ferocious assaults of Syria’s civil war.

Regime forces have been engaged in a ferocious assault on Ghouta since February 18, killing more than 500 people.