The last operating hospital in east Aleppo has been destroyed by airstrikes, leaving up to 250,000 residents without access to surgery or specialist care, and rebel-held districts at the point of collapse.

Another four hospitals were hit and forced to close on Friday, before the Omar bin Abdul Aziz facility was struck just after 8.30pm, capping the most deadly day yet for the medical system in Syria’s second city, which has been systematically targeted by Russian and regime jets over the past year.

“They have all been repeatedly attacked over the last few days,” said David Nott, a surgeon with decades of experience working in war zones, who has been supporting the Aleppo doctors.

“I don’t think in all my years of doing this I’ve seen such dreadful pictures of injuries, of people lying on the floor in an emergency room, the dead mixed with the living,” said Nott. At least two doctors were among the dead, he said, and he feared hospitals that had kept operating under attack and with dwindling supplies might now have been shut down permanently.

“The Aleppo hospitals have been re-opened so many times, underground or in new locations, but between the bombing and the siege I don’t know if it will be possible to resurrect them this time.”

The destruction comes amid a blitz of opposition areas spearheaded by Russia over the past three days, which has whittled away what remains of the opposition-held east in preparation for a ground invasion, led by Iranian-backed militias allied to Syrian forces.

Médecins Sans Frontières said east Aleppo’s hospitals had been hit by bombs in more than 30 separate attacks since the siege began in July and there was no possibility of sending help or more supplies.

Schools, roads and homes have also been bombed repeatedly as the Syrian leader’s allies attempt to drive opposition communities out of the city and, by doing so, change the face of the nearly six-year war. Doctors and residents inside Aleppo said there was no more than two weeks’ supplies of food and medicines left inside the city.

In the lead-up to the US election, Russia had pledged to obliterate what remained of anti-regime forces and the communities that support them, and as president-elect Donald Trump prepares to take over the White House, Moscow is acting on its threats.

Condemnation of the latest attacks was swift, with medical organisations and aid agencies that support the city’s healthcare system labelling them as “war crimes”. Governments were slower to react, with Turkey, the opposition’s most important backer, remaining silent as the attacks had intensified. Turkish forces continue to back a rebel push against the Isis stronghold of al-Bab, 25 miles to the northeast of Aleppo.

There was no immediate response from Washington, which has supplied light arms to some opposition groups for the past three years, but has refused requests to introduce battle-changing weaponry, such as anti-aircraft missiles. Trump has indicated he will withdraw US support from anti-Assad rebels soon after his inauguration in January.

Russia has said its latest campaign is directed at the terror group, along with Jabhat Fatah al-Sham, a prescribed terror organisation with links to al-Qaida. It said it was focusing its efforts on Homs and Idlib, closer to the Mediterranean coast.

On Friday, Russia’s ambassador to the UK, Alexander Yakovenko, said Russia’s bombing aimed to ensure that Isis members did not enter the area from Mosul in Iraq, where the organisation is besieged by the Iraqi military, militias fighting in support of it, and Kurds. In response, the UK’s special representative for Syria, Gareth Bayley, tweeted: “How is that geographically sensible … that’s 400km from border with Iraq?”

Farida, a doctor living in southeastern Aleppo, said: “It’s unnatural, we’ve seen so much bombardment but nothing like this ever. It is hell. We wanted to try to set up a maternity ward somewhere else because ours was damaged in the bombing of the hospitals but we couldn’t leave the house. They want life to end in Aleppo.

“They cannot take it from the ground, so they’re trying to take it from the air. They bombed all the hospitals and schools, so there is no life and people give up. If it stays like this, people cannot wait it out.

“Medicines, vaccines, will finish. At this rate I cannot see us continuing for more than two weeks.

“I cannot predict the scenario [in two weeks], that is if there is still anyone living in Aleppo by that time.

“Nobody cares about us. We’re just Arab Sunnis living in Aleppo. If we had one Frenchman in Aleppo the whole world would have risen up. There is no longer any humanity. The wounded are dying, a patient whose stomach is open in the operations room has to be abandoned, women are leaving delivery rooms still bleeding because the hospitals are getting attacked, babies are dying because oxygen tanks are empty and generators aren’t working.”