Beirut: The Syrian army advanced within firing range of the rebels' sole supply route to Aleppo in heavy fighting Thursday despite its announcement of a ceasefire for the Eid al-Fitr holiday, a monitor said.
Saudi-backed rebel group Jaish al-Islam (Army of Islam) said four of its fighters were killed trying to stop the army from cutting the Castello Road, the only route into rebel-held areas of Syria's second city.
Rebel fire on the government-held Sayf al-Dawla district of the city killed three people, the Syrian Observatory for Human Rights said.
The army announced on Wednesday that it was observing a 72-hour nationwide ceasefire for the Eid al-Fitr holiday that marks the end of the Islamic holy month of Ramadan.
But fighting has continued on the ground, particularly in and around Aleppo.
President Bashar al-Assad`s forces have been trying to cut the Castello Road for more than two years and the Observatory said that Thursday`s advance brought them the closest so far to achieving that goal.
Their capture of a hill just a kilometre (less than a mile) away allows them to fire on any traffic moving along the road from the ground as well as from the air, the Britain-based monitoring group said.
"If government forces can hold their positions there and fight back the counter-offensive, then the opposition neighbourhoods will be completely besieged," Observatory head Rami Abdel Rahman said.
Aleppo has been divided since mid-2012 when rebels seized the east of the city confining government forces to the west.
The pre-war commercial capital has been one of the main battlegrounds of the civil war ever since and successive ceasefires announced for the city have been swiftly broken.