Chubby legs resting on the pedals of a bicycle and a decapitated head are all that are left of a boy killed on Thursday when Syrian warplanes blitzed the rebel-held town of Maaret al-Numan.

Rescue workers told an AFP correspondent the boy was among 44 people killed when government jets raided the town in northwestern Syria's Idlib province, which rebels captured on October 9.

The boy's distressed parents, imploring Allah, rushed to retrieve what was left of him: a torso imbedded in rubble, horribly mutilated legs covered in dust and his head.

The body of another boy who was playing further down the street was torn to bits by shrapnel.

A few metres (yards) away an apartment block has been flattened, trapping all its residents inside except for a woman who miraculously escaped unscathed.

She was lounging at home in her pyjamas when the planes struck. Dazed but alive she climbs out through the window to get out.

The air strikes destroyed a four-storey building and damaged another apartment block as well as a mosque, where many women and children had taken refuge.

"We have recovered 44 corpses from under the rubble," one rescue worker told an AFP correspondent at the scene. But Doctor Nader Jaafar Sharhub, working out of a makeshift hospital, said 20 were killed and 30 were missing.

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

Another resident said several of the dead had just returned from Kafr Nabal, a town west of Maaret al-Numan. "They thought the danger had passed."

Most of the town's 125,000 residents had fled in the face of relentless air raids since the rebels seized Maaret al-Numan earlier this month.

Thursday's raids targeted the southern part of town, an area that had so far been spared the wrath of government troops battling an armed insurgency.

At a field hospital in a public school, the AFP journalist saw 12 corpses wrapped in white sheets, and plastic bags marked "body parts."

"Look at what those dogs are doing," someone shouted as reporters witnessed the carnage.

"Go to hell Bashar. You've killed children," screamed another, referring to Syrian President Bashar al-Assad.

Residents wounded in the air strikes, their faces bloodied, were rushed to another makeshift hospital set up in the basement of a government building.

Several fighter jets flew over Maaret al-Numan and the surrounding area throughout Thursday morning, making short dives to drop at least 10 bombs on the town and its eastern outskirts, near the Wadi Deif army base, which is under rebel siege.