Fierce fighting erupted late Monday between Syrian regime forces and the Islamic State militants over the control of a key supply route for the regime to Aleppo, a monitoring group said.
The heavy battles taking place on the Khanasir-Ithriya road south-east of Aleppo, came three days after Islamic State fighters cut off the regime's road linking the northern city to government territory in central Syria, the Britain-based Syrian Observatory for Human Rights reported.
By night fall Islamic State militants managed to take over Al-Tharyan checkoint, a regime checkpoint in the area, killing at least eight Syrian troops, the Observatory said.
Earlier the watchdog said some 15 kilometres of the route was under the effective control of Islamic State units positioned on or near it.
The road is the only link to the government-controlled western half of Aleppo, with the main highway north from the central cities of Hama and Homs controlled by rebels.
Islamic State launched a major assault on the route on Friday in an apparent response to gains by government forces trying to relieve hundreds of troops besieged at the Kuweires air base in territory controlled by the jihadists east of Aleppo.
Control of Aleppo city, Syria's largest before the war, is divided between the government in the west and rebels in the east.
In 2013 Syrian troops opened the Khanasir road through desert territory east of the country's main north-south highway, allowing them to resume land supplies to western Aleppo.
Syrian troops backed by Hezbollah and Iranian fighters and Russian warplanes have also gained ground against rebels south of Aleppo over the past 10 days.
Activists and aid groups have warned that tens of thousands of civilians have fled the area, many reduced to sleeping in the open.
The United Nations said on Monday that at least 120,000 people have been displaced in Aleppo, Hama and Idleb governorates in northern Syria since early October.
"People have been mostly displaced within the affected governorates where they lived, close to their original towns and villages, while others have fled to camps near the Turkish border," said Stephane Dujarric, a UN spokesman in New York.
He noted that people fleeing Aleppo have moved to towns west of the city.
Syria's conflict has driven more than half the country's pre-war population of 22.4 million people from their homes, with almost 4.7 million seeking refuge abroad.
More than 250,000 people are estimated to have been killed in the conflict, which began as peaceful pro-democracy protests in 2011.
In Palmyra central Syria, the Observatory said the Islamic State Jihadist group blew up three historic columns in the ancient city while it conducted an execution of three men.
The watchdog said the incident took place on Sunday when the Jihadist group tied the three men it had arrested for unknown reasons from Palmyra to the columns and executed them by blowing up the three columns.
It was not clear which columns were destroyed.
Islamic State, which has previously destroyed ancient monuments in neighbouring Iraq as well as Christian and Islamic sites in both countries, captured Palmyra from government forces in May.
Palmyra is a registered UNESCO World Heritage Site since 1980 and is located on an oasis in the central Syrian desert, it was a major trading centre.
Since May the jihdist group had destroyed multiple sites and historic artifacts, including Palmyra's celebrated temples of Bel.
In September, three of the tower tombs that stood outside the ancient city of Palmyra for almost 2,000 years have been destroyed by the Jihadist movement.
Meanwhile, Syria's embattled president Bashar al-Assad met Monday with the foreign minister of Oman, Yusuf bin Alawi, Syrian state media reported.
The state news agency SANA said the Omani diplomat confirmed his country's commitment to take every possible measure to help resolve the Syrian crisis.
The visit by the Omani official came amid heightened diplomatic efforts to find a solution to the Syrian crisis and few days after al-Assad paid a surprise visit Moscow.
By Weedah Hamzah, Emoke Bebiak
