For a sixth straight day, warplanes flown by government forces and their allies have pounded the densely populated enclave east of the capital, the last rebel bastion near Damascus.

The civilian casualties and devastation there are among the worst in Syria since the government captured rebel-held parts of Aleppo in intense fighting in 2016.

At least 462 people have been killed and many hundreds injured, the Syrian Observatory for Human Rights monitoring group says. The dead include at least 99 children. Syrian state media reported one person was killed and 58 injured from rebel shelling of sites in Damascus, including a hospital.

Eyes were on Moscow, and whether President Bashar al-Assad’s veto-wielding ally would support the U.N. Security Council’s draft ceasefire resolution, block it, or seek to water it down in a way that would let bombing go on.

The vote, which aims to clear the way for aid deliveries and medical evacuations, was postponed for at least an hour to 12 p.m. EST (1700 GMT), said Kuwait’s U.N. mission, the council president for February, amid a flurry of last-minute negotiations on the text drafted by Sweden and Kuwait. 

Russian Foreign Minister Sergei Lavrov said earlier on Friday that Moscow wanted guarantees that rebel fighters will not shoot at Damascus residential areas.

Previous ceasefires have a poor record of ending fighting on the ground in Syria, and Moscow has a history of blocking Security Council measures that would harm Assad’s interests.

Syria’s government, with its allies Russia, Iran and Shi‘ite militias, has often used the tactic of pushing rebels to surrender their strongholds after long sieges and military offensives.

Insurgents in eastern Ghouta have vowed not to accept such a fate, ruling out an evacuation of fighters, their families and other civilians of the kind that ended rebellion in Aleppo and Homs after heavy bombardment in earlier years.

“We refuse categorically any initiative that includes getting the residents out of their homes and moving them elsewhere,” Ghouta rebel factions wrote in a letter to the Security Council on Friday.

Eastern Ghouta has 400,000 people spread over a larger area than other enclaves the government has recaptured. Late on Thursday, government aircraft dropped leaflets urging civilians to depart and hand themselves over to the Syrian army, marking corridors through which they could leave safely.