Rebels downed a helicopter on Wednesday as troops fought to take back a key Syrian town, a watchdog said, as international peace envoy Lakhdar Brahimi warned the conflict risks setting the region ablaze.
Fighting for control of the Damascus-Aleppo highway raged around the northwestern town of Maaret al-Numan even as Brahimi appeared to have won tentative support for a ceasefire proposal.
Brahimi, the UN and Arab League envoy, warned of the conflict spreading in the Middle East as he visited neighbouring Lebanon, the latest leg of a regional tour aimed at ending more than 19 months of bloodshed.
"This crisis cannot remain confined within Syrian territory," the veteran troubleshooter told reporters in Beirut.
"Either it is solved, or it gets worse... and sets (the region) ablaze. A truce for (the Muslim holiday of) Eid al-Adha would be a microscopic step on the road to solving the Syria crisis."
Brahimi called this week for a temporary ceasefire in Syria during the four-day Eid al-Adha holiday starting on October 26.
"The Syrian people, on both sides, are burying some 100 people a day," he said on Wednesday.
"Can we not ask that this toll falls for this holiday? This will not be a happy holiday for the Syrians, but we should at least strive to make it less sad.
"If the Syrian government accepts, and I understand there is hope, and if the opposition accepts," a truce would be a step "towards a more global ceasefire," said Brahimi.
The Syrian conflict began in March 2011 with pro-reform protests inspired by the Arab Spring uprisings.
It has since transformed into a civil war pitting mainly Sunni rebels against President Bashar al-Assad's regime, which is dominated by his minority Alawite sect, an offshoot of Shiite Islam.
At times it has also spilled over into neighbouring countries, including Lebanon and Turkey.
Tensions have soared between Turkey and Syria with Ankara taking an increasingly strident line towards its southern neighbour since a shell fired from inside Syria killed five Turks on October 3.
Brahimi has been promoting the idea of a ceasefire during Eid al-Adha on the tour that has included stops in Sunni-ruled Egypt, Turkey and Saudi Arabia, as well as Shiite-led Iran and Iraq.
Damascus says it is prepared to discuss the proposal in talks with Brahimi while the exiled opposition says it would welcome any ceasefire but insists the ball is in the government's court to halt its daily bombardments.
"The Syrian side is interested in exploring this option and we are looking forward to talking to Mr Brahimi," Syrian foreign ministry spokesman Jihad Maqdisi told AFP.
The opposition Syrian National Council said it expected the rebel Free Syrian Army to reciprocate any halt to the violence but that it was up to the government to act first.
"We would welcome any halt to the killings but we think the appeal needs to be addressed first to the Syrian regime, which has not stopped bombarding Syrian towns and villages," SNC leader Abdel Basset Sayda told AFP.
On the battlefront, rebels shot down a helicopter gunship in the country's northwest as the army fought to recapture the strategic town of Maaret al-Numan, said the Syrian Observatory for Human Rights.
"In Maarhtat, on the outskirts of Maaret al-Numan, rebel fighters downed a helicopter being used in the fighting," the group said, adding it crashed in nearby Bsida according to initial reports.
Regime warplanes targeted a rebel blockade of a highway in Idlib province which has halted the regime's efforts to get reinforcements to Aleppo, theatre of intense fighting for the past three months, said the Observatory.
The early morning air raids targeted Maaret al-Numan and nearby villages, which fell to the rebels a week ago as they pushed their quest to create a northern "buffer zone" abutting Turkey, it said.
The clashes erupted as rebels attacked a six-tank convoy of government troops in the town of Maarhtat as it was making its way to reinforce the nearby Wadi Deif army base, the largest in the region.
At least five people were killed across Aleppo province, including in the city of the same name, as government forces pounded the area and clashed with rebels who fired rockets into an army base, said the Observatory.
The Observatory -- which relies on a network of activists, medics and lawyers for its information -- says some 33,000 people have been killed since the revolt began in March last year, among them 2,300 children.