"We are yet again appalled by the recent reports of the Assad regime's use of chemical weapons and the escalation of bombings that has resulted in dozens of civilian deaths in the last 48 hours", the statement said.
In Beirut, an official with Hezbollah said the group has no presence in the area hit by the coalition, adding that those who came under fire were pro-Assad forces known as the Popular Committees, as well as the Syrian National Defense Forces.
Home to an estimated 400,000 people, the Eastern Ghouta region has been included in a de-escalation deal that was meant to bring calm.
But on Wednesday, as we reported, regime-backed forces attacked Syrian opposition troops, accompanied by USA advisers.
Youth in Eastern Ghouta "are being starved, bombed and trapped", said Sonia Khush, Save the Children's Syria response director.
At the same time the current United Nations humanitarian co-ordinator in Syria challenged the Assad regime directly in an unprecedented way, saying the organisation "cannot remain silent any longer" because of the "dramatic deterioration" in terms of escalating civilian suffering as starvation and death so common place.More news: Tesla Share Price Remains High From the Rocket Man Effect
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Among them were at least 58 children, the Observatory said.
Eastern Ghouta, which lies just east of the capital Damascus, is controlled by rebel factions including Islamists.
The letter also said the Syrian government wants the "illegal" USA -led coalition dissolved, as it is "a force of protection and support to terrorism".
Russia's U.N. Ambassador Vassily Nebenzia said he will raise the coalition's airstrike during closed consultations later Thursday in the U.N. Security Council.
U.S. State Department spokesperson Heather Nauert said the United States supports the UN ceasefire call.
Iran's IRNA news agency confirmed the Israeli attack after it quoted the General Command of the Syrian Army, which said in a statement that "warplanes of the Israeli enemy at 3:42 a.m on Wednesday fired several missiles from inside Lebanese airspace at one of our military positions in the Damascus countryside".
"We estimate more than 100 Syrian pro-regime forces were killed while engaging SDF and coalition forces", Reuters quoted the official as saying.