Rescue workers and conflict monitors said Russian planes carried out the airstrikes. Russia’s Defense Ministry denied involvement.
The rebel-held enclave of Eastern Ghouta has long defied Syrian President Bashar al-Assad’s attempts to restore his rule over the Damascus region, and his army, backed by Russia, has pushed in recent weeks to divide the area into three pockets of opposition control.
Thousands of civilians have escaped to government territory since Thursday. Many of them, dazed and exhausted, have told traumatic stories of oppression by the rebels who controlled their towns. But thousands more have run in the other direction, fearing vengeance by the security forces they resisted during Syria’s 2011 uprising.
The Syrian Observatory for Human Rights, a Britain-based monitoring group, said Friday that 80 people were killed across the enclave. Describing the Kfar Batna attack Friday, Siraj Mahmoud, a spokesman for the White Helmets rescue group, said the victims had been stockpiling food for their families.
“They were trying to find food,” he said. “People have been trying to buy flour, anything, just to eat.”
In a video briefing Friday at the United Nations Security Council, Staffan de Mistura, the U.N. envoy for Syria, described fresh allegations that incendiary weapons were being used against civilians in Eastern Ghouta, as well as “disturbing” reports that munitions have been laced with chlorine, a chemical weapon.
Life in the enclave, he said, has become “hell on earth.”
In waging the offensive, the Assad government has ignored a Security Council resolution urging a cease-fire, as well as repeated calls from the Trump administration for all sides to stop the fighting.
The Russian Defense Ministry, for its part, denied reports Friday that Moscow has continued airstrikes or combat missions of any kind over Eastern Ghouta.
“This is just more fake news,” said a ministry spokesman, Maj. Gen. Igor Konashenkov. He added that more than 16,000 people have left the area through humanitarian corridors secured by Moscow.
As Syria enters its eighth year of violence, Western diplomats say the offensive has underscored the extent to which Russia is directing the conflict, 2½ years after it intervened to turn the tide in Assad’s favor.
“Unless we can impress upon the Russians that this is catastrophic to their broader objectives in Syria, then I don’t see this ending very well at all,” a European official said at a recent briefing.
But analysts monitoring the conflict see few signs that the offensive was working contrary to Moscow’s interests.
“Russia has never paid a direct cost for its actions in Syria,” said Emile Hokayem, a senior fellow for Middle East security at the International Institute for Strategic Studies. “Its current strategy is to escalate things precisely to drive home the point that there is no possible counterescalation, and that ultimately, as long as Russia can shape battlefield dynamics, then they will always get away with what they are doing militarily.”
The Syrian army said in a statement Friday that its forces have captured and cleared dozens of villages, towns and farms in the area. Military operations were “swift and decisive,” said Brig. Gen. Ali Mayhoub.
More than 1,300 people have been killed and thousands more wounded since the offensive began Feb. 18.
In a sign of just how internationalized the Syrian conflict has become, the Syrian Observatory for Human Rights also said Friday that Turkish shelling and airstrikes have killed 27 people in the northern Kurdish-held town of Afrin.
After a sluggish start, the Turkey-backed offensive has gathered pace in recent weeks, leaving the area’s Kurdish militants encircled.
Matthew Bodner in Moscow and Zakaria Zakaria in Istanbul contributed to this report.