Syrian rebels shot down a helicopter on Wednesday as troops tried to retake a key town, AFP reported.
According to the report, the rebels shot down a helicopter gunship as the army fought to recapture Maaret al-Numan. Amateur video posted on YouTube showed a helicopter spiraling downwards and exploding, as onlookers cried "Allahu akbar!"
Warplanes targeted the rebel blockade of the highway that has halted regime efforts to reinforce Aleppo.
The early morning raids targeted Maaret al-Numan and nearby villages that fell to the rebels a week ago as they pushed to create a "buffer zone" abutting Turkey, the Observatory said.
The fighting flared as rebels attacked a convoy of tanks in the town of Maarhtat as it headed for Wadi Deif army base, the area's largest.
Violence killed at least 108 people nationwide on Wednesday, including 33 civilians, the Observatory told AFP.
Meanwhile, UN-Arab League envoy Lakhdar Brahimi warned that the conflict in Syria risks setting the region ablaze. His remarks were made after he appeared to have won tentative support for a ceasefire, the report said.
The UN and Arab League envoy warned of the conflict spreading as he visited neighboring Lebanon, the latest leg of a Middle East tour aimed at ending more than 19 months of bloodshed in Syria.
"This crisis cannot remain confined within Syrian territory," he told reporters, according to AFP. "Either it is solved, or it gets worse... and sets (the region) ablaze."
Brahimi said a truce for the four-day Muslim Eid al-Adha holiday from October 26 would be "a microscopic step on the road to solving the Syria crisis."
"The Syrian people, on both sides, are burying some 100 people a day," said Brahimi.
"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.
Arab League chief Nabil al-Arabi, who met Brahimi on Tuesday, backed the call for an Eid truce, also asking for international support.
Brahimi’s spokesman, Ahmad Fawzi, told AFP the envoy would "soon go to Damascus."
His tour has already taken him to Egypt, Saudi Arabia and Turkey, as well as Iran and Iraq.
Damascus says it is ready to discuss the truce proposal with Brahimi while the exiled opposition says it would welcome any ceasefire but insists the ball is in the government's court.