WHILE international powers squabbled over who was to blame for the collapse last week of the fragile ceasefire in Syria (News, 16 September), government troops begana new offensive on rebel-held Aleppo.

In the early hours of Wednesday morning, soldiers loyal to the Assad regime began to move into the parts of the city held by opposition forces after days of unrelenting air strikes that have killed hundreds of civilians and demolished hospitals.

Since hostilities re-erupted last week, Russia and the United States have been trading angry statements, and each has accused the other of being at fault.

The UN Special Envoy for Syria, Staffan de Mistura, has urged them to put aside their differences and resurrect the ceasefire, for the good of the suffering people of Syria. Mr de Mistura told an emergency session of the UN Security Council that he was appalled by the ferocity of the military assault on Aleppo, the besieged second city of Syria, where fireballs from incendiary bombing were “lighting up the pitch darkness”.

The bombing of the city of two million people was unprecedented in its intensity, Mr de Mistura said. The Council must find a way to end hostilities in Syria: there should be a ceasefire, weekly two-day pauses in fighting to allow aid in, and space for medical evacuations.

Russia, which is supporting the Syrian regime with air strikes and military assistance, has said that the US and its allies are at fault; while the US has suggested that Russia’s words of peace are “blatantly contradicted” by its actions.

A US-led air strike on a Syrian army base killed 60 people last week, although Washington has insisted that it had not intended to attack the base, and that the bombing was a mistake.

Soon afterwards, an aid convoy waiting to go into Aleppo was bombed, with the loss of 30 civilians, prompting the UN to suspend its operations. This time, the US pointed the finger at Russia, saying that only its planes were in the sky at the time. Russia said that neither it nor its Syrian allies were responsible.

A subsequent joint statement on Saturday by the foreign ministers of the US, the UK, France, Germany, Italy, and the EU further condemned Russia for not facilitating a diplomatic solution.

“The outrageous bombing of a humanitarian convoy; the Syrian regime’s public denunciation of the cessation of hostilities; continuing reports that the regime is using chemical weapons; and the unacceptable ongoing regime offensive on eastern Aleppo, supported by Russia, blatantly contradicts Russia’s claim that it supports a diplomatic resolution,” the statement said.

The foreign ministers said that they wanted to destroy Islamic State (IS) and other terrorist groups in Syria, but also deplored the Syrian government’s attempts to hold up deliveries of humanitarian aid. “Patience with Russia’s continued inability or unwillingness to adhere to its commitments is not unlimited,” they warned.

Speaking at the Security Council, the US Ambassador to the UN, Samantha Power, said that Russia and its Syrian allies were “laying waste to what is left of an iconic Middle Eastern city. . . Instead of peace, Russia and Assad make war. Instead of getting life-saving aid to Syrians, Russia and Assad are bombing hospitals and first responders.”

Russia’s Permanent Representative to the UN, Vitaly Churkin, replied that Syrian troops were attempting to force terrorists out of Aleppo while harming as few civilians as possible.

The Russian Foreign Minister, Sergey Lavrov, speaking at the UN General Assembly on Friday, criticised the West, accusing it of desiring its own supremacy over the needs of other nations. While Russia had prevented the “legitimate” Assad regime from collapse under attack from “terrorists”, the US and its allies must re-commit themselves to defeating IS.

Mr de Mistura said that reports from the ground revealed that at least 213 civilians had been killed by air strikes on Aleppo and the surrounding region, as bombs hit residential buildings across the besieged eastern part of the city. If such systematic targeting of civilian areas was confirmed, it could amount to proof of war crimes, he said.

The charity Save the Children said that aid workers in Aleppo were finding that at least half of the casualties in the current offensive were children.