Much of the fighting has been marked by indiscriminate shelling, missile attacks, and aerial bombardment, killing scores of civilians across Idlib and Aleppo. The rebels do not have an air force.
The Britain-based Syrian Observatory for Human Rights reported 26 air strikes across Idlib, one of the last remaining opposition bastions.
Observatory head Rami Abdurrahman said Russian and government air strikes on the north-western province have intensified since rebels launched a campaign from Idlib to break a government siege of Aleppo’s opposition districts on July 31. The strikes have killed 122 civilians, he said.
Another 327 civilians, including 126 children, have been killed in fighting in Aleppo province, according to the Observatory, which monitors both sides of the conflict and gathers information from a network of activists inside Syria.
The toll includes 126 people killed by rebel shelling of government-held parts of Aleppo city. Tens of thousands of Syrians displaced from Aleppo have found refuge in Idlib, home to a pre-war population of 1.5 million.
The Local Co-ordination Committees, an activist network, said that Russian jets struck the towns of Jisr al-Shaghour and Binnish, while the Observatory reported strikes on the provincial capital, Idlib. It was unclear how the activists identified the planes.
Aleppo, once Syria’s largest city and commercial capital, is now the focal point of the civil war and the only major city where the opposition to President Bashar Assad still has a foothold.
The rebel campaign, spearheaded by ultraconservative factions including the al-Qaida-linked Jaish Fatah al-Sham, formerly known as the Nusra Front, has drawn manpower from Idlib, some 30km to the west. A spokesman for the ultraconservative Ahrar al-Sham faction confirmed the rebels were drawing recruits from Idlib.
“The battle for Aleppo concerns all of Syria,” said Abu Khaled, who gave only his alias. At least 97 rebel fighters from Idlib have died in combat in Aleppo since July 31, according to Mr Abdurrahman.
Aleppo is still home to two million people, most of whom live in the government-controlled western districts.
Last night, rebels opened a new front, sending a truck bomb into the western Zahraa neighbourhood, according to the Twitter account of the Islamic Front, one of the factions fighting for the city.
The Observatory reported fighting in the city’s western and southern districts.
To the east, a Kurdish-led force known as the Syria Democratic Forces drove the IS group out of the strategic town of Manbij on Saturday and announced a new campaign against al-Bab, a nearby town held by the extremists.