At least 25 people have been killed in northwestern Syria in air strikes carried out by the Syrian government and Russia, the Syrian opposition-run rescue service known as the White Helmets says.
Russian and Syrian jets struck the rebel-held city of Idlib in northern Syria on Sunday, military sources said, as President Bashar al-Assad vowed to crush insurgents who had swept into the city of Aleppo.
The army also said it had recaptured several towns that rebels had overrun in recent days.
Residents said one attack hit a crowded residential area in the centre of Idlib, the largest city in a rebel enclave near the Turkish border where around four million people live in makeshift tents and dwellings.
At least seven people were killed and dozens injured, according to rescuers at the scene. The Syrian army and its ally Russia say they target the hideouts of insurgent groups and deny attacking civilians.
Ten children were among the dead in the air strikes in and around Idlib and other targets in rebel-held territory near Aleppo on Sunday, according the White Helmets.
The total death toll from Syrian and Russian strikes since November 27 had climbed to 56, including 20 children, the group added in a statement on X.
The insurgents are a coalition of Turkey-backed mainstream secular armed groups along with Hayat Tahrir al-Sham, an Islamist group that has been designated a terrorist outfit by the US, Russia, Turkey and other states.
The insurgents seized control of all of Idlib province in recent days, the boldest rebel assault for years in a civil war where front lines had largely been frozen since 2020.
Insurgents also swept into the city of Aleppo, east of Idlib, on Friday night, forcing the army to redeploy.
In remarks published on state media, Assad said: "Terrorists only know the language of force and it is the language we will crush them with".
The Syrian army said dozens of its soldiers had been killed in the fighting in Aleppo.
Russian war bloggers reported on Sunday that Moscow had dismissed Sergei Kisel, the general in charge of its forces in Syria, after insurgents swept into Aleppo. Reuters has requested comment from the Russian defence ministry.
In a joint statement, the United States, France, Germany, and Britain urged "de-escalation by all parties and the protection of civilians and infrastructure to prevent further displacement and disruption of humanitarian access".
Inside Aleppo city, streets were mostly empty and many shops were closed on Sunday as scared residents stayed at home. There was still a heavy flow of civilians leaving the city, witnesses and residents said.
Aleppo had been firmly held by the government since a 2016 victory there, one of the war's major turning points, when Russian-backed Syrian forces besieged and laid waste to rebel-held eastern areas of what had been the country's largest city.
Rebels said on Sunday they had pushed further south of Aleppo city and captured the town of Khansir in an attempt to cut the army's main supply route to Aleppo city.
Rebel sources said they had also captured Sheikh Najjar estate, one of the country's major industrial zones.
Reuters could not independently confirm the battlefield accounts.
The war, which has killed hundreds of thousands of people and displaced many millions, has ground on since 2011 with no formal end. Most heavy fighting halted years ago after Iran-backed militias and Russian air power helped Assad win control of all major cities.
