Worse than a slaughterhouse

Russian or Syrian warplanes knocked two hospitals out of service in the beseiged rebel sector of Aleppo yesterday and ground forces intensified an assault in a battle which the United Nations said had turned the city into a slaughterhouse.

Meanwhile, the United States yesterday threatened to suspend its engagement with Russia over the intensifying violence.

Two patients died in one of the hospitals and other shelling killed six residents queueing for bread under a siege that has trapped 250,000 people with food running out.

The week-old assault, which could herald a turning point in the war, has already killed hundreds of people, with bunker-busting bombs bringing down buildings on residents huddled inside. Only about 30 doctors are believed to be left inside the besieged zone, coping with hundreds of wounded a day.

UN chief Ban Ki-moon denounced the attacks -- which saw the two largest hospitals in Aleppo's opposition-controlled east hit with air strikes and artillery fire -- as "war crimes".

President Bashar al-Assad's forces and his ally Moscow have carried out a barrage of air strikes on eastern Aleppo since Syria's regime announced a bid last week to retake all of the divided city.

The latest bombardment has been some of the worst in Syria's five-year civil war, and comes after the failure of a short-lived ceasefire brokered by Russia and the United States earlier this month.

Moscow and Washington have traded blame over the truce's collapse, with the US harshly criticising Russia's participation in the Aleppo offensive.

Yesterday, US Secretary of State John Kerry warned Russian counterpart Sergei Lavrov that Washington will end talks on the Syrian conflict unless Moscow halts the assault on Aleppo.

Kerry said the burden was on Russia to stop the assault and ensure humanitarian aid access, his spokesman John Kirby said.

Lavrov, on his part, urged Kerry to make good on US pledges to separate Washington-oriented units of Syrian opposition from "terrorist groups", Russia's Foreign Ministry said yesterday.

Yesterday's attacks saw the M10 and M2 hospitals hit before dawn, forcing both to shut temporarily, said Adham Sahloul of the Syrian American Medical Society, which supports both hospitals.

It was unclear who had carried out the bombings, which UN chief Ban denounced before the Security Council.

"Those using ever more destructive weapons know exactly what they are doing. They know they are committing war crimes," he said. "Imagine the destruction. People with limbs blown off. Children in terrible pain with no relief," he said. "Imagine a slaughterhouse. This is worse."

The UN children's agency UNICEF said at least 96 children have been killed and 223 wounded since Friday in the rebel-held sections of Aleppo where the health system was crumbling with only 30 doctors left.

More than 170 people have been killed in east Aleppo since Syria's army announced its operation to retake the city, said the Syrian Observatory for Human Rights.