ISLAMABAD: A Pakistani airliner carrying 152 people crashed in a ball of flames Wednesday into densely wooded hills outside Islamabad amid heavy rain and poor visibility, killing everyone on board.

Rescue officials said pieces of charred flesh and body parts were littered around the smouldering wreckage, partially buried on a remote hillside, in the deadliest crash involving a Pakistani passenger jet in 18 years.

Private airline Airblue`s flight ED 202 from Karachi was being diverted into land at Islamabad`s Benazir Bhutto International airport when witnesses saw it flying at an unusually low altitude before a defeaning boom.

The plane disintegrated into a gorge between two hills, enveloped in cloud and some distance from the road, severely hampering rescue efforts and limiting visibility for helicopters hovering overhead, said an AFP correspondent.

"I saw a big ball of smoke and fire everywhere with big pieces of aircraft rolling down the hill," said police official Haji Taj Gul.

"The plane was flying very low. Then we heard a loud noise," said Wajih-ur Rehman, a resident of the exclusive E-7 neighbourhood in the Margalla foothills, home to Western expatriates and some of Pakistan`s elite.

"Nobody survived," Interior Minister Rehman Malik told Express TV. Bodies were mostly mutilated and in pieces, and would require identification, he said.

The civil aviation authority and Airblue said there were 152, including six crew, on board the doomed plane.

Zeeshan Haider, a Civil Aviation Authority official said seven children, including two babies, were on the flight manifest.

Reports had said a handful of people survived the disaster, but asked whether all those on board died Malik replied: "Yes, all of them are dead".

"It`s a big tragedy. It`s really a big tragedy," the minister said.

The US embassy said two Americans were on the flight.

"I can confirm there were two American citizens on the plane and we are working with Pakistani authorities as we normally do in cases such as this," embassy spokesman Richard Snelsire told AFP.

Officials said air traffic control diverted the plane on its final approach, owing to rain and thick cloud -- outside the normal route for aircraft flying up from the southern port city of Karachi.

The civil aviation authority said all possible causes would be investigated, including terrorism and bad weather, although officials gave no indication that an attack might have been to blame.

"The investigation teams will probe every possible reason behind the crash ranging from the bad weather to terrorism," said Riaz-ul-Haq, the authority`s deputy director.

Rescue official Arshad Javed told AFP of horrifying scenes at the crash site after a routine commuter flight turned to carnage.

"All we could see were charred hands or feet. I collected two heads, two legs and two hands in a bag.

"We shouted if anyone was there alive, but heard no voice," he said.

"The wreckage of the plane is buried under the debris. First machines have to be deployed there to remove debris off the hill and then we can reach to pull out bodies or survivors -- if any."

Police said the wreckage was scattered in three directions.

"Bodies were found in pieces. We have found equipment which may be the blackbox. Now experts will examine it," said city police chief Bani Amin.

The government declared a day of national mourning and called off a cabinet meeting as Prime Minister Yousuf Raza Gilani expressed his grief over the "tragic incident" and offered prayers for the dead.

Anguished families were in tears after hearing of the disaster while waiting to meet their relatives at the Islamabad arrivals terminal.

"We cannot explain our agony, we don`t know if he is alive," said Bilal Haider, who had come to collect his younger brother Abbas returning from a trip to Karachi for a job interview.

Airblue spokesman Raheel Ahmed told AFP the Airbus 321 took off from Karachi before 8:00 am (0300 GMT), and said bad weather could have been to blame.

"There was no technical fault in the plane when it took off," he said.

Airbus said the single-aisle plane was a relatively young 10 years old, and the European company offered its full assistance to Pakistani investigators.

Airblue is one of Pakistan`s most respected airlines. It has been operating only since 2004, using new Airbus A320 and A321 aircraft on domestic routes and international services to Dubai, Sharjah, Abu Dhabi, Muscat and Manchester.

Pakistan enjoys a relatively good air safety record.

The most recent fatal commercial crash was a Pakistan International Airlines Fokker F27 that came down in July 2006, killing 45 people on takeoff from the central city of Multan, bound for Lahore.

The deadliest civilian plane crash involving a Pakistani jet was a PIA Airbus A300 that crashed into a cloud-covered hillside on its approach to the Nepalese capital Kathmandu, killing 167 people in September 1992.

BDST: 1826 HRS, July 28, 2010