MAARET AL-NUMAN, Syria :Syrian fighter jets on Thursday blasted the rebel-held town of Maaret al-Numan, killing at least 44 people, rescue workers said, adding urgency to calls for a truce by peace envoy Lakhdar Brahimi.

"We have recovered 44 corpses from under the rubble," one rescue worker said. A medic had earlier told AFP that at least 20 people were killed and 30 were missing.

A number of children were among those killed when warplanes bombed an apartment block in the strategic northwestern town, which was captured by rebel fighters on October 9 in their push to create a buffer zone along the Turkish border.

An AFP reporter at the scene said one child was decapitated while the body of a second, still on his bicycle, was pulled from the rubble.

With fighting raging across Syrian flashpoints, Damascus announced that Brahimi would travel to Damascus on Saturday on the last leg of a regional tour aimed at securing a ceasefire during a Muslim holiday next week.

Brahimi, the UN-Arab League special envoy to Syria, said in Lebanon on Wednesday that the crisis risks setting the region "ablaze".

The conflict began in March 2011 with pro-reform protests inspired by the Arab Spring, but is now a civil war pitting mainly Sunni Muslim rebels against President Bashar al-Assad's regime dominated by his minority Alawite sect, an offshoot of Shiite Islam.

Brahimi is due to arrive in Damascus on Saturday morning for talks with Foreign Minister Walid Muallem, foreign ministry spokesman Jihad Maqdisi said.

Asked whether any optimism was warranted over the Algerian diplomat's visit, Maqdisi told AFP: "Let's see what Brahimi has to say."

Serious doubts have been raised about Brahimi's plan to halt the bloodshed, even temporarily.

"I don't know whether they will all agree at the higher level or not on the ceasefire proposal, but on the ground you have pro- and anti-regime forces that do not respond to any authority," said Rami Abdel Rahman of the Syrian Observatory for Human Rights.

"There would most likely be a problem of implementing the truce," he told AFP.

Damascus said it is ready to discuss with Brahimi his proposal for a four-day ceasefire during the Muslim holiday of Eid al-Adha from October 26.

The exiled opposition said it would welcome any ceasefire but insisted the ball is in the government's court to halt its daily bombardments.

Paul Salem, director of the Carnegie Middle East Centre in Beirut, said that such a short-term truce was "possible, but it will not be strategic or permanent".

"I doubt the truce will initiate a political process, because the conditions for such a process are lacking both in Syria and the international community," said Salem.

On the battlefront, warplanes pounded Maaret al-Numan on the Damascus-Aleppo highway, with one strike flattening an apartment block, said the AFP correspondent in the town.

Relatives, their faces covered in white dust, screamed as they attempted to find their loves ones.

"Go to hell, Bashar for killing our children!" survivors shouted. "God give us the strength to defeat these bastards!"

Rescue workers said at least 40 people had been killed.

"We have received at least 20 dead bodies, many were children," doctor Nader Jaffar Sharhoub said, as he rushed to treat the wounded in a makeshift hospital set up in a school. "There are some 30 people still missing."

The AFP journalist saw 12 corpses wrapped in white sheets, and plastic bags marked "body parts."

"At the moment it seems only three people survived the attack, including a two-year-old child," said Sharhoub. "He survived in the arms of his dead father."

The rebels attempted but failed to shoot down the warplanes, while setting tyres alight to produce columns of thick black smoke in an attempt to restrict the visibility of the pilots.

Nearby, the insurgents backed by jihadists launched an intense mortar attack on a besieged army base with about 250 troops holed up inside at Wadi Deif, Idlib's largest.

In Aleppo, Syria's most populous city in the north of the country, the military pounded rebel-held neighbourhoods of Shaar and Sukkari, as well as two nearby villages, the Observatory said.

"What we are seeing in Aleppo is a repeat of the (central city of) Homs scenario" with multiple fronts and the vast majority of residents of areas affected by violence having fled, said the Observatory's Abdel Rahman.

"We hope democracy comes soon to Syria, but meanwhile, we can envisage a long war in areas such as Aleppo," he added.

The Observatory said that outside Maaret al-Numan at least 38 people were killed in Syria on Thursday, adding to a death toll of more than 32,000 since the uprising began.