More than 460 civilians, including over 100 children, have been killed in nearly a week of bombardment that has been one of the seven-year Syrian conflict's bloodiest episodes -- and rescuers were searching for more bodies buried in the rubble.

Frantic diplomatic haggling delayed a vote at the United Nations Security Council on a 30-day truce as the leaders of France and Germany pleaded with Russian President Vladimir Putin, whose jets are also bombing the enclave, not to veto the plan.

Regime-backer Moscow has demanded "guarantees" that the truce would be respected by rebel fighters, and Kuwait's Ambassador Mansour al-Otaibi, who holds the council presidency this month, insisted diplomats "were almost there".

Amid the wrangling US President Donald Trump slammed the actions of the Syrian government and its Russian and Iranian supporters as a "humanitarian disgrace".

Few of Eastern Ghouta's nearly 400,000 residents -- mostly living in a scattering of towns across the semi-rural area east of the capital -- ventured out on Friday.

An AFP correspondent in Douma, the enclave's main town, saw a handful of people stealthily crossing rubble-strewn streets to assess damage to their property or look for food and water.

He said rescuers carried a young boy wounded in the eye, blood trickling down his face, to one of the town's hospitals. "Will I see again?" he asked a doctor.

Death has fallen from the sky relentlessly since government and allied forces intensified their bombardment on Sunday and rocket fire soon forced everybody to run for cover.

Exhausted and famished families cowered in cramped and damp basements, exchanging information on the latest casualties of the government's blitz.

Some of the only people braving the threat of more bombardment were medical staff in those hospitals still standing and rescuers sifting through the wreckage of levelled buildings.

- Trapped bodies -

Fresh strikes on Friday, by the Syria regime and its Russian ally, killed at least 38 civilians, including 11 children, the Syrian Observatory for Human Rights said.

Rami Abdel Rahman, head of the Britain-based war monitor, said the strikes targeted different areas of Eastern Ghouta.

The latest deaths brought to 468 the number of people killed -- including 108 children -- since the regime and Russia intensified their bombardment of the besieged area on February 18.

More than 2,000 people have been wounded.

Rebels have been firing back into the capital Damascus, where on Friday a hospital was hit, the official Syrian news agency SANA said.

Diplomats at the United Nations failed to clinch Russian approval late Thursday on a resolution calling for a 30-day truce to allow for humanitarian aid and medical evacuations.

They then announced that a vote would take place on Friday, but it was delayed twice amid staunch Russian resistance.

Negotiations were continuing to avoid a Russia veto of the text that would establish a truce to allow humanitarian aid deliveries and medical evacuations.

German Chancellor Angela Merkel and French President Emmanuel Macron wrote to Putin to ask him to back the ceasefire.

The latest text softens language in a key provision to say that the council "demands" a ceasefire instead of "decides".

It also specifies that the ceasefire will not apply to "individuals, groups, undertakings and entities associated" with Al-Qaeda and the Islamic State group. A previous version simply mentioned the two groups.

World leaders have expressed outrage at the plight of civilians in Eastern Ghouta, which UN chief Antonio Guterres called "hell on earth", but have so far been powerless to halt the bloodshed.

"The UN says it is concerned and calls for a ceasefire, France condemns, but they have given us nothing," said Abu Mustafa, one of the few civilians on the streets of Douma Friday morning.

"Every day we have strikes, destruction. This would draw tears from a rock," said the 50-year-old, who was escorting a wounded person to hospital.

- Toothless response -

The enclave has been controlled by Islamist and jihadist groups since 2012.

The main rebel groups in Eastern Ghouta rejected in a statement released Friday any deal that would see them or other residents relocated.

"We categorically reject any initiative providing for inhabitants to leave their homes and be transferred towards any other location," they said in a letter addressed to Guterres.

The area is completely surrounded by government-controlled territory and residents are unwilling or unable to flee the deadly siege.

The dire images of civilian victims bleeding to death in understaffed hospitals and the scope of the urban destruction have shocked the world and drawn comparisons with the devastating 2016 battle for Aleppo.

The aid community has voiced its frustration at being prevented from assisting civilians in Eastern Ghouta, which has been under government siege since 2013.

"The blocking of this resolution is another failure to end human suffering in Syria, with the UN Security Council rendered impotent as this senseless war rages on," Thomas White, Syria director at the Norwegian Refugee Council, told AFP.

Government forces have this month reinforced their deployment around the enclave in preparation for a ground offensive.