BEIRUT: Rebel shelling killed eight children at a school in the government-held part of Aleppo on Sunday and a barrel bomb killed a family of six in the rebel-held area, part of a heavy government bombardment that has knocked out all the hospitals. Hundreds of people have been killed since Tuesday in a concerted push by the government and its allies to quash resistance in the rebel-held eastern part of Aleppo to reestablish control over Syria's biggest pre-war city. On Sunday they advanced into the Hanano district on its northern edge, but rebels said the battle was still continuing and that some of the pro-government forces' gains had been reversed. The bombardment, one of the most intense in the almost six year-old civil war, has taken a heavy toll on civilians. Two medics said the al-Baytounji family had suffocated to death because the barrel bomb, which fell in the Sakhour district at about midnight, had been laced with chlorine gas. The Syrian Observatory for Human Rights, which monitors the war, confirmed the bombing but could not confirm that chlorine gas was used. Damascus has denied use of the gas, which would contravene the international Chemical Weapons Convention. Rebel shelling killed at least eight children, aged from six to 12 years, among 10 deaths in the Saria Hasoun school in al-Farqan district, the Observatory and Syrian state television reported. The bombardment of eastern Aleppo drew condemnation on Sunday from the EU's humanitarian aid commissioner, Christos Stylianides. 'The relentless bombing of East Aleppo by the Syrian regime in the last few days has now left hundreds of thousands of besieged civilians without access to food and to functioning hospitals,' he said. An official with a rebel group based in east Aleppo said there were still no working hospitals there on Sunday, a day after the World Health Organization reported that bombing had put them all out of action. Hospitals have previously been brought back into service after being knocked out through bombing in the rebel-held area but food supplies are running low. The military and Russia's air force had paused their bombardment of eastern Aleppo, except for on the frontlines, for two weeks after a month-long offensive from late September to late October, but recommenced strikes on Tuesday.