Syrian rebel groups have repelled advances by the Islamic State of Iraq (ISIL) in a series of villages along the Turkish border and cleared ISIL fighters from a nearby gas factory.

Fighting was raging on Monday between ISIL and a loose coalition of Syrian rebels in villages near the towns of Azaz and Marea in the northern province of Aleppo, Al Jazeera's correspondent in Aleppo reported.

Backed by US-led coalition strikes targeting ISIL positions, the rebels took the gas factory in Doudian village, which had been used as a base for ISIL.

The villages lie along the rebels' supply line from Turkey, which is a major backer of Syria's opposition.

The ISIL losses come just days after several rebel groups, including the powerful Ahrar al-Sham and al-Jabha al-Shamya (the Levant Front) coalition, announced a major military operation against ISIL in border villages.

The US-led coalition launched their first round of air strikes against ISIL in Iraq in August 2014, followed by air strikes on ISIL targets in Syria during September 2014.

The air raids, combined with rebel force activity throughout northern Syria, have increased the pressure on ISIL, which controls large swathes of Syria's east and several pockets in the north.

To the south of Aleppo province, opposition fighters on Monday were also battling President Bashar al-Assad’s troops who were trying to advance into the rebel-held al-Rashdeen neighbourhood in the city of Aleppo.

The city has been divided between government forces and rebels since 2012.

The fighting in the country's north came as residents of Douma, in the suburbs of the capital Damascus, were burying the dead following air strikes on a market in the town, which killing at least 110 people and injuring more than 300.

On Monday, the UN humanitarian chief condemned the attacks against civilians in Syria.

"I am horrified by the total disrespect for civilian life in this conflict," Stephen O'Brien said, a day after one of the bloodiest incidents in the four-year war.

Source: Al Jazeera and agencies