DAMASCUS: Rebels seized a town on the highway to Aleppo on Tuesday in what monitors said was a blow to regime plans to reinforce troops in the northern city, the main battleground of Syria's nearly 19-month conflict.
The rebel advance on the town of Maaret al-Numan, in the northwestern province of Idlib, came after twin suicide bombings hit an air force compound near Damascus, killing dozens of people, said the monitoring group.
Turkey, meanwhile, again warned Syria it would not hesitate to retaliate for any strike on its soil as the country's top military commander visited troops stationed along the reinforced border.
And with fighting spilling into both Turkey and Lebanon, UN chief Ban Ki-moon urged President Bashar al-Assad's regime to declare a unilateral truce while NATO head Anders Fogh Rasmussen urged restraint.
On the increasingly bloody battlefield, rebels overran Maaret al-Numan on the highway linking Damascus with Aleppo after a fierce 48-hour gunbattle and heavy shelling, said the Syrian Observatory for Human Rights.
"Regular forces pulled back from all of their checkpoints around Maaret al-Numan, except for one at the entrance of the town," said Observatory director Rami Abdel Rahman.
"This is a strategic location on the route from Damascus to Aleppo. All the regime reinforcements headed to Aleppo must pass through Maaret al-Numan."
The rebels' seizure of the town came as soldiers moved into Homs, farther south on the same highway, in a bid to finish off insurgents in the central city and free up forces for northern battle zones like Aleppo.
"This is your tank, O Bashar!" a group of about 20 rebels shouted in a video posted by activists online as they fired off celebratory gunfire at a captured army checkpoint.
State television, meanwhile, said troops entered the rebel district of Khaldiyeh in the besieged city of Homs.
An activist confirmed the army had "stormed part of Khaldiyeh," but the Observatory said the neighbourhood remained in rebel hands, although fighting was intense.
"The catastrophe is that there are 800 families trapped in Homs. It will be an unprecedented massacre if they take over the district," said the activist, who identified himself as Abu Bilal.
The army onslaught around Homs sparked a new exodus of refugees into neighbouring Lebanon, with up to 400 people fleeing from the nearby area of Qusayr within 24 hours, a Lebanese security official said.
'All hell has broken loose'
Many of the villagers crossed the heavily mined border on foot, while others came by motorbike or donkey, an AFP correspondent in the Lebanese frontier town of Arsal reported.
"All hell has broken loose on our village. Many people have died, and many others have fled," said one refugee who identified himself only as Masri. "Our village is now practically empty."
Pro-government media remained silent on Monday night's twin suicide bomb attacks in Harasta, a town northeast of Damascus.
A security official said, however, that the assault had been largely foiled, although some people were hurt when one vehicle blew up.
The blasts were claimed by the jihadist Al-Nusra Front, which said one attacker drove a booby-trapped car and a second an explosives-packed ambulance.
The Observatory's Abdel Rahman said "dozens of people" died in the bombings, and that the fate of "hundreds of prisoners" held in the building's basement was unknown.
AFP was unable to verify either account.
The Observatory said the attacks sparked intense fighting in Harasta.
UN chief Ban urged a unilateral truce by Assad's regime.
"I have conveyed to the Syrian government (a) strong message that they should immediately declare a unilateral ceasefire," he said.
Ban urged "the opposition forces to agree to this unilateral ceasefire when and if the Syrian government declares it," and appealed for countries to stop arming both sides.
Turkish Prime Minister Recep Tayyip Erdogan warned of retaliation against Syria's "aggressive position."
"It has become inevitable for our armed forces to retaliate in kind... as the Syrian administration maintains its aggressive position," he told lawmakers.
Erdogan spoke as his armed forces chief inspected troops on a tour of the heavily fortified border after a number of shells landed on Turkish soil, including one strike that killed five civilians last week.
The Observatory said violence across Syria killed at least 100 people on Tuesday. It said more than 32,000 people have died since the revolt against Assad erupted in March 2011.