The torso of a woman was recovered Friday from the site of Pakistan's worst aviation disaster, as bodies were returned to families and investigators scoured a third day for the crucial black box.

The Airblue passenger jet slammed into forested hills overlooking the Pakistani capital in heavy rain and poor visibility on Wednesday as it came into land after flying from Karachi, killing all 152 people on board.

The search and recovery operation was hampered for two days by torrential monsoon rains and low cloud, but resumed Friday as the weather cleared, allowing teams to trek from the road to the debris on the hillside.

Abdul Jalil, a rescue worker, told AFP that the upper portion of a woman's body had been recovered, adding to the grim harvest of charred flesh and human remains that have been collected from at least 115 of those on board.

Investigators are now focusing on the aircraft's black box, hoping the flight data recorder will provide valuable clues to the fate of the 10-year-old Airbus 321, which was piloted by an experienced captain.

"Investigators are here. Technical experts are here. A team from the Civil Aviation Authority along with a five-member team from Airbus in France are now on the hilltop," said Malik Oliya, a city administration official.

"These people are examining the crash site to investigate the causes of the crash. They are searching for the black box and any other clue."

The crash was the worst aviation tragedy on Pakistani soil, piling more woes on a country that is on the frontline of the war on Al-Qaeda and where Islamist militant bombers have killed more than 3,570 people in the past three years.

Pakistan came under fire from British Prime Minister David Cameron and Afghan President Hamid Karzai this week after the leak of thousands of secret US files accused the country of double dealing with the Taliban in Afghanistan.

Another 200 people have been killed by torrential rains, and on Monday eight people died when a Taliban suicide bomber targeted the mourning for a cabinet minister's only son in the northwest.

Questions about the plane crash have focused on why the pilot was flying the jet so low over the craggy Margalla Hills in a restricted flight zone.

Airblue, one of Pakistan's most respected airlines, has been tight-lipped about any possible technical fault or pilot error.

Reports that the pilot was told to take another route were mere speculation, company spokesman Raheel Ahmad told AFP.