Doctors in Eastern Ghouta are struggling to keep up with an influx of patients injured by the Syrian government offensive that they say is targeting civilians and hospitals.

Nearly 300 people have been killed and 1,400 wounded since the attacks on the only rebel-held area near Damascus started earlier this week. On Wednesday morning, 24 people died in government strikes, according to the UK-based Syrian Observatory for Human Rights.

Late on Wednesday, Russia UN Ambassador Vassily Nebenzia called on the UN Security Council to meet on Thursday to discuss the situation.

"This is necessary given the concern that we've heard today in order to make sure that all parties can present their vision, their understanding of this situation and come up with a ways of getting out of this situation," Nebenzia said.

In addition to air strikes and shelling, rescue workers and residents told MEE that the government has been dropping barrel bombs on residential neighbourhoods, accounts backed up by images posted on social media.

When the regime attacks a shelter, it becomes overwhelming because we are dealing with 15-20 people all at once - Dr Ataya Malik

Amid the targeted strikes and already depleted medical supplies after a four-year siege, medics say the situation is becoming untenable.

"We don't have enough ambulances left to ferry the injured, meaning many people die before they reach us," Dr Ataya Malik told MEE.

"The hospitals have been overflowing with blood. We are doing what we can to help, but the situation is becoming unbearable."

Medicine Without Borders reported on Wednesday that 13 facilities it supports inside Eastern Ghouta have been bombed since Monday; Physicians for Human Rights (PHR), another medical NGO, said that eight facilities it assists were hit. It was not immediately clear if there was overlap between the facilities.

PHR called the attacks "blatant war crimes" that have become "an everyday feature" in the war.

A man carries an injured boy as he walks on rubble of damaged buildings in the rebel-held besieged town of Hamouriyeh in Eastern Ghouta (Reuters)

Ten operations in one day

Dr Ataya Malik and other physicians say the attacks on facilities have only compounded an already impossible job.

"When the regime attacks a shelter, it becomes overwhelming because we are dealing with 15-20 people all at once," said Dr Ataya Malik.

"No matter if they are family or friends, as doctors, we have to continue our work to save as many lives as possible. Saving a single life is a massive achievement for us."

Dr Mohammed Salem, the coordinator of primary care in the Directorate of Health of Damascus and a local surgeon, said now that most of the equipment has been destroyed, conditions in the hospitals still open are very primitive.

We are underground. We don't have equipment or electricity - Dr Mohammed Salem

"We are underground. We don't have equipment or electricity," he said.

Dr Rida, who is also treating patients in the area, told MEE that medical teams have been working at "full capacity".

"On Tuesday, I did 10 operations. One of the cases involved me having to amputate someone's leg," said Rida who declined to give his last name due to concerns around safety.

"The main target from what we have seen are civilians. This bombardment is a tactic being used to silence the revolution."

Residents head underground as Eastern Ghouta is pounded by government forces (Reuters)

'This madness has to stop'

Several UN agencies condemned the latest escalation in violence on Tuesday as the Syrian government continued to pummel the rebel enclave.

Russia, which has propped up Assad's government since 2015, claimed rebels had wounded four people on Wednesday with mortar bombs, and six were killed on Tuesday.

"Today, residential areas, Damascus hotels, as well as Russia's Centre for Syrian Reconciliation, received massive bombardment by illegal armed groups from eastern Ghouta," said Russia's defence ministry on Tuesday.

Kremlin spokesman Dmitry Peskov on Wednesday described as "groundless" accusations that Russia bears some of the blame for civilian deaths in Eastern Ghouta.

About 400,000 people still live under siege in the enclave, including hundreds in urgent need of medical care outside the enclave.

Valerie Szybala, executive director of the Washington-based Syria Institute, said that this is the "first time" barrel bombs have been used to such a degree in Eastern Ghouta.

Everyone is depleted both physically and militarily - Valerie Szybala, Syria Institute

"One of the main reasons they haven't used barrel bombs much in Ghouta until now is because the rebels were able to take down helicopters," Szybala told MEE.

"But now, thanks to the siege, everyone is depleted both physically and militarily."

Aid groups have said their assistance can no longer reach those in need due to the heavy bombardment and have warned of an unfolding catastrophe.

The International Committee of the Red Cross (ICRC) called on Wednesday for humanitarian access to Ghouta, especially to reach wounded people in critical need of treatment.

"The fighting appears likely to cause much more suffering in the days and weeks ahead," said Marianne Gasser, ICRC's head of delegation in Syria. "This is madness and it has to stop."

An injured man at a medical point in the besieged town of Douma, Eastern Ghouta (Reuters)

'This is preliminary bombing'

A commander in forces fighting Assad's government told the Reuters news agency that the bombing aimed to prevent the rebels from targeting the eastern areas of Damascus with mortar bombs.

"The offensive has not started yet. This is preliminary bombing," the commander said.

Another commander, Suheil al-Hassan, in a video said: "I promise, I will teach them a lesson, in combat and in fire.

"You won’t find a rescuer. And if you do, you will be rescued with water like boiling oil. You’ll be rescued with blood.”

This article is available in French on Middle East Eye French edition.