Syrian forces backed by Russian warplanes have continued to hit the rebel enclave of Eastern Ghouta, with at least 27 killed on Wednesday. This brings the number of civilian deaths to more than 270, including 60 children, over the past three days.

The civilians who lost their lives on Wednesday morning were in the town of Kafr Batna, according to Syrian Observatory for Human Rights and Syrian Civil Defence, also known as the White Helmets.

More than 300 others were wounded in one of the most fierce attacks in the area since 2013 when a gas attack killed more than 100.

The "relentless" bombing, which Amnesty International said amounted to war crimes, has damaged or destroyed six hospitals and medical centres across the city, residents say.

"We stopped comprehending where the bombing is coming from, either from the sky or the ground," Khalid Abulwafa, an ambulance driver and member of the Syrian Civil Defence, told Al Jazeera.

"We arrive at a site that has been hit, and immediately another attack follows… we just run to pull out as many people as possible before it's too late," he said.

"Multiple raids hit different areas at the same exact time… we don't have the ability to rush to all the areas at once."

Earlier this week, the United Nations and other international bodies expressed outrage at the number of civilian casualties. The UN called for an "immediate" stop to the "escalation" of violence.

'Traumatised' children

Amina Abdulrahman lost two children in the latest round of attacks.

"The shrapnel [from an air raid] ripped through the walls, killing Ahmed and Abir, who were barely 10 years old," she told Al Jazeera.

"There was nothing I could do to save them…I had to bury my two 10-year-old children."

Mahmoud Ajam, a resident of the suburb, said he cannot console his traumatised children.

"At night, I wrap myself and the kids under a blanket and try to help them go to sleep. I tell them everything will be back to normal the day after, and that they'll be able to go to school," he told Al Jazeera.

"But the day after, there is more and more shelling, and they can't forget the scenes I try hard to help them overcome," he said.

Eastern Ghouta is the last remaining rebel-held area east of Damascus and has been under siege by Syrian President Bashar al-Assad's forces since 2013.

Aid workers struggle to treat the wounded with basic medical equipment and damaged facilities.

"Civil Defence bases have been targeted throughout Eastern Ghouta. We lost valuable equipment and members of our team," Abulwafa, the aid worker, said.

"The regime is deliberately killing civilians," he said.

According to Abdelwahab Abu Yahia, a field surgeon, the "horrendous" number of those wounded has become overwhelming to deal with.

"They come in waves, like a mother and her children for instance," he told Al Jazeera.

"Our medical centre was hit in four air raids yesterday, which caused significant damage to the facility and the services it offers…Hospitals across the entire city have been bombed," Abu Yahia added.

"There are no words to describe what is happening."

Al Jazeera's Zeina Khodr, reporting from Beirut, said the Syrian government is sending troops and reinforcements to the edges of Eastern Ghouta.

"The aim is to bomb people into submission, to force them to surrender," she said from the capital of neighbouring Lebanon.

"The government wants the rebel enclave to surrender; they want thousands of rebels in Eastern Ghouta to lay down their arms and leave to other rebel-held areas."

Another means of pressure is the imposition of a "crippling" blockade that has been in place for more than four years.

The siege has left some 400,000 people in dire need of food and medicine. Despite continuous calls by rights organisations for an immediate ceasefire and for the government to lift the siege, aid convoys have not been able to deliver much of the desperately needed supplies.

As such, overall access to the enclave remains "woefully inadequate", the UN has said.

The lack of commodities has left residents with two main - and scarce - options to stay afloat, including rice and bread.

Abdulrahman, who lost 10-year-old Ahmed and Abir, says she now does everything in her power to protect her three other children and "never" lets them out her sight.

"We sleep and eat together and never leave the house at all," she said.

"And sometimes, my husband and I don't eat for days at a time to feed our children with the ongoing food shortages."

Additional reporting by Zouhir Al Shimale