Syria said on Tuesday that it was interested in exploring a proposal by the UN and Arab League peace envoy for a truce later this month even as it unleashed multiple air strikes on rebel positions on a key highway.
The Syrian Observatory for Human Rights said the pre-dawn air raids around Maaret al-Numan were the "most violent" since insurgents captured the strategic town on the Damascus-Aleppo road last week.
The Syrian foreign ministry said it looked forward to talks with envoy Lakhdar Brahimi on his proposal for a ceasefire for the four-day Muslim Eid al-Adha holiday which he has been promoting on a regional tour.
But ministry spokesman Jihad Maqdisi stressed that for a halt to the violence, the rebels and their backers would also need to be involved.
"In order to succeed in any initiative, it takes two sides," Mr. Maqdisi said in answer to a question from AFP.
"The Syrian side is interested in exploring this option and we are looking forward to talking to Mr. Brahimi to see what is the position of other influential countries that he talked to in his tour," he said.
"Will they pressure the armed groups that they host and finance and arm in order to abide by such a ceasefire?"
Mr. Brahimi was in Cairo on Tuesday on the latest leg of a regional tour that has already taken him to Turkey and Saudi Arabia, staunch backers of the opposition, and Iran, Syria's closest ally.
Mr. Brahimi's office said the envoy had appealed for Iranian help to broker the truce.
"He reiterated the call by UN Secretary General Ban Ki-moon for a ceasefire and a halt to the flow of arms to both sides. A ceasefire, he said, would help create an environment that would allow a political process to develop," his office said.
The UN chief had previously called for a unilateral ceasefire by the Syrian government to be matched by the rebels only afterwards, but that idea was rejected by Damascus as its troop losses mount.
Syrian warplanes targeted the rebel blockade of the highway to Aleppo, theatre of intense fighting for the past three months, the Observatory said, adding that rebels responded with anti-aircraft fire.
"Since this morning, there have been 29 air strikes on the area of Maaret al-Numan," said Observatory chief Rami Abdel Rahman. "Most civilians from the area have fled."
Army shelling of nearby Kafr Nabal killed two children, aged six and 10, said the Observatory, adding they were among at least 78 people who died in bloodshed around the country.
Another five children under the age of six died along with two adults in shelling of homes at Mayadeen village in the eastern province of Deir Ezzor, added the Britain-based group.
The Observatory – which relies on a network of activists, medics and lawyers for its information – says children account for 2,300 of the 33,000 people killed in the conflict.
The escalation in Idlib province, which borders Turkey, came as a senior U.S. official visited Ankara for talks on the conflict in Syria amid heightened tensions between the two neighbours.
"We continue to consult with our partners in the region including Turkey on a variety of issues related to Syria," U.S. embassy spokesman in Ankara, T.J. Grubisha, told AFP.
Tensions between Syria and Turkey have soared as Ankara and Damascus banned flights from each other's airspace after Ankara confiscated a cargo of radar equipment from a Syrian flight from Moscow last week.
On October 3, five Turkish civilians were killed by cross-border fire against the rebels that Syria says are receiving arms from Gulf Arab states through Turkey.
The United States has called on all Syria's neighbours to monitor their airspace carefully.
"We are encouraging all of Syria's neighbours to be vigilant with regard to how their airspace is used, particularly now that we have this concrete example," State Department spokeswoman Victoria Nuland said.
A day after the European Union imposed a 19th round of sanctions on Damascus, Switzerland said it has blocked 100-million francs (about $106-million Canadian) in assets linked to the Syrian regime.
The UN food agency said prices for basic provisions have nearly doubled in Syria since the conflict erupted, and that it has failed to deliver supplies to 100,000 people because of the spiralling fighting.
Syrian state news agency SANA, meanwhile, announced by-elections on December 1 to fill five seats in parliament, two of which became vacant when sitting MPs defected to the opposition.