The slain Jihadi rebels, including those with the al-Qaida-linked Nusra Front, were killed during a failed overnight attempt to re-open their last remaining supply route in the northern countryside of Aleppo, after the Syrian army cut it off Thursday, according to the Syrian Observatory for Human Rights.
Rebels launched an attack inside Aleppo early on Monday, shelling Syrian government-held areas and clashing with government-allied forces. Groups fighting under the banner of the Free Syrian Army (FSA) say however that they control the rebel-held part of the city.
"There is a need to adopt a new strategy to push the peace process by adopting a tougher policy against the regime's violations against the Syrian people... before calling for a new round of negotiations", the HNC statement said.
The Castello Road was effectively severed by government forces on Thursday when they seized a hilltop within firing range of the key supply line.
The attacks, which involved the shelling of regime-held neighbourhoods and intense street fighting, came just days after the advance by the regime side towards the Castello Road.
The Damascus government controls the war-torn country's major population centres in the west, with the exceptions of Idlib and rebel-held areas of Aleppo.
Government forces are fighting insurgents for control of Castello Road, which connects opposition-controlled eastern Aleppo with the western inland.
The regime of silence also didn't stop the rebels from raining down on government-controlled areas in Aleppo with tens of improvised rockets, which killed 40 people and wounded over 300 others on Friday.
"There are very few vegetables today because the Castello Road is closed", said Abu Mohamed, a vendor in the Bustan al-Qasr neighbourhood.
Its capture brings the Syrian government closer to its long-standing objective of encircling rebel-held areas of the northern city.
In the central province of Homs, regime air strikes killed eight civilians, including three children from the same family and a further three from another, the Observatory said.
More than 280,000 people have been killed in Syria since the conflict began in March 2011 with anti-government protests that sparked a deadly crackdown.
U.S. Secretary of State John Kerry on Wednesday had welcomed the Syrian army's announcement of the truce, adding that discussions were underway to try to extend it.
"All kinds of heavy artillery and machine-guns are being used in the assault, which is meant to ease the pressure on the Mallah and Handarat fronts", he said, referring to areas near the rebel supply route into Aleppo.
The Nusra Front has meanwhile played a significant role in fighting against pro-government forces southwest of Aleppo.