A Syrian alliance has forced fighters from the Islamic State of Iraq and the Levant (ISIL) group away from one of its key supply routes on the border with Turkey, according to a UK-based monitoring group.
The opposition coalition captured al-Bal village in northern Aleppo from ISIL on Friday, in a major advance towards the Bab al-Salama border crossing, which is just 10km away, the Syrian Observatory for Human Rights reported.
The village's recapture came after heavy fighting, which killed at least 14 opposition fighters and 15 ISIL members, Rami Abdel Rahman, head of the Syrian Observatory, said.
Further south, fighters were battling to defend the town of Marea, on the road between the crossing and the opposition-held eastern sector of Aleppo city.
Activists said the opposition forces were simultaneously launching their own attacks on ISIL positions in the area.
"The ultimate goal for ISIL is to cut off this crossing," Abdel Rahman said.
Mamun Abu Omar, the head of a local opposition press agency, said: "ISIL is trying to surround the town by occupying the villages all around it."
The opposition fighters are battling both ISIL and government forces in Aleppo province.
Meanwhile, in the eastern part of the country, the Syrian Kurdish YPG group, backed by other Syrian opposition groups, have reportedly pushed further into ISIL's stronghold of Raqqa province, in an attempt to capture a strategic town.
Redur Xelil, a YPG spokesperson, told Reuters news agency the YPG and smaller Syrian Arab groups fighting alongside it have begun on Saturday to move towards Tel Abyad, situated near the Turkish border.
Blockade of Suluk
The advance came as the YPG blockaded the neighbouring ISIL-controlled town of Suluk.
"The move towards Tel Abyad from the east began today after the completion of the Suluk blockade," Xelil said via Skype.
"Many of the Daesh [ISIL] militants have fled [Suluk], apart from a group of suicide attackers inside the town and the booby traps, so we are very cautious about entering the town centre."
Special Report Syria: Broken Nation
Tel Abyad is important to ISIL because it is the nearest border town to its de facto capital, Raqqa city.
Turkey says thousands of people have already fled across its border to escape fighting between YPG and ISIL near Tel Abyad.
YPG has made a determined push into Raqqa province from neighbouring Hasakah, where it has driven ISIL fighters from wide expanses of territory since early May.
The Syrian Observatory said the opposition forces were now halfway between Suluk and Tel Abyad.
The reports of ISIL's setbacks could not be independently confirmed by Al Jazeera.