Pro-government forces pounded the rebel-held district of eastern Ghouta outside the Syrian capital Damascus on Tuesday, in a surge of violence that a war monitor said had killed at least 250 people since Sunday night.
The Britain-based Syrian Observatory for Human Rights said it was the highest 48-hour death toll in the Syria conflict since the 2013 chemical attack on eastern Ghouta, the last major rebel bastion located near the capital.
The wave of airstrikes, rocket fire and shelling has sparked international condemnation. France, a permanent member of the U.N. Security Council, described the bombardment as a serious violation of international humanitarian law.
There was no immediate comment from the Syrian military. The regime says it only targets militants.
Recent violence in the besieged suburb is part of a wider surge in fighting on several fronts as President Bashar Assad's military pushes to end the seven-year rebellion against him.
The Observatory said the bombardment had killed more than 106 people in eastern Ghouta on Tuesday alone.
Panos Moumtzis, the U.N. humanitarian coordinator for Syria, on Tuesday condemned the bombing of five hospitals in eastern Ghouta and said intentional attacks on medical facilities "may amount to war crimes."
U.S. State Department spokeswoman Heather Nauert said Washington was "deeply concerned" by the rising violence in Ghouta.
"The Assad regime's siege and starve tactics are … adding to the humanitarian disaster there," she said.
Nauert said the United States supported a U.N. call for a monthlong cessation of hostilities to allow for the delivery of aid and an emergency medical evacuation of civilians. She urged Russia to stop supporting the Assad government.
In Brussels, Syrian opposition leader Nasr al-Hariri – a delegation head at stalled U.N. peace talks – pleaded for more international pressure on Assad to stop.
In Geneva, the U.N. children's agency expressed outrage at the casualties among children, saying it had run out of words.
At least 58 children have been killed since the escalation began on Sunday. Another 1,200 people have been injured in the bombardment, the Observatory said.
Rescuers said the air raids created "a state of terror" among residents in eastern Ghouta, where the United Nations says nearly 400,000 people live. The pocket of satellite towns and farms has been under government siege since 2013.
Factions in Ghouta fired mortars at Damascus on Tuesday, killing six people and injuring 28, Syrian state TV said. The army retaliated and pounded militant targets, according to the state-run Syrian Arab News Agency.
The Syrian Foreign Ministry accused militants in Ghouta of targeting Damascus and using people as "human shields." It said in a letter of complaint to the United Nations that some Western officials were denying the government's right to defend itself.
The Civil Defense in eastern Ghouta, a rescue service that operates in rebel territory, said jets battered Kafr Batna, Saqba, Hammouriyeh and several other towns on Tuesday.
"The warplanes are not leaving the sky at all," said Siraj Mahmoud, a civil defense spokesman in Ghouta, as the sound of explosions rang out in the background.
Mahmoud said that government forces bombed houses, schools and medical facilities, and that rescuers had found more than 100 people dead "in one day alone," on Monday.
Assad's most powerful backer, Russia, has been pushing its own diplomatic track which resulted in establishing several "de-escalation zones" in rebel territory last year.
Fighting has raged on in eastern Ghouta even though it falls under the cease-fire plans brokered by Russia with the help of Turkey and Iran. The truces do not cover a former al-Qaida affiliate that has a small presence in the besieged enclave.
Residents and aid workers say the "de-escalation" deals have brought no relief. Food, fuel and medicine have dwindled.
The two main rebel factions in eastern Ghouta, which signed the deals with Russia last summer, accuse Syria and Russia of using the jihadist presence as a pretext for attacks.
Russia did not comment on the renewed bombing in eastern Ghouta on Tuesday.
On Monday, Russian Foreign Minister Sergey Lavrov blamed "armed provocations" by Nusra Front militants, formerly linked to al-Qaida, for conditions in Ghouta. He said Moscow and its allies could "deploy our experience of freeing Aleppo … in the eastern Ghouta situation."
U.N. Syria envoy Staffan de Mistura warned on Tuesday that the escalating battle in Ghouta could turn into a repeat of the bloody fight for Aleppo, over which the Assad regime regained full control in late 2016 after years of fighting.
