Private airliner Air Blue operated Airbus A-321, flying from Turkey to Islamabad via Karachi, hit the Margalla Hills near Daman-e-Koh viewpoint at approximately 10 am in thick fog, said the police.
The police said bodies of the passengers were strewn across the low mountains near the scene of the smouldering wreckage in inaccessible hills, shrouded in heavy cloud and fog during a downpour.
Up to 10 people were confirmed dead but five injured survivors were airlifted from the crash site by helicopters, according to Interior Minister Rehman Malik. The inaccessibility of the site and bad weather were hampering rescue efforts, he said.
"Rescue teams, paramilitary Pakistan Rangers and senior police officials have reached the site. The weather is unfriendly but still some helicopters reached the site and airlifted five survivors to the hospital," Malik said.
Rescue workers had to trek for over an hour to reach the site. "They have been directed to remove any survivors on stretchers," Malik said.
Rescue workers said they had pulled out 10 bodies from the wreckage. Earlier, Islamabad Capital Development Authority Chairman Imtiaz Inayat Elahi had said rescue workers were doing their best to reach the site but it was unlikely that there would be any survivors. Islamabad has been hit by heavy rains for the past few days and the city was covered by fog and low clouds.
TV news channels quoted Air Blue officials as saying that there were 159 passengers on board the ill-fated aircraft, which had taken off from Karachi at 7.50 am. The officials did not specify the number of crew members. With rescue efforts hit by bad weather and smoke and fire at the crash site, a spokesperson for the state-run Rescue 1122 service said helicopters had been sought from the military.
"We have sought helicopters from the army's aviation wing and a counter-terrorism body. We will need at least eight to 10 helicopters because of the inaccessibility of the area," she said.
The crash occurred in an area that is not easily accessible as the Margalla Hills are covered by thick forests. City residents said that they had seen the Air Blue aircraft flying 'very low' over Islamabad shortly before the crash.
"I heard a loud bang and then saw smoke rising over the Margalla Hills," said Aman Ali, a schoolboy. Interior Minister Malik said the aircraft was at 2,600 feet when it was cleared to land. It then rose up to 3,000 feet before disappearing from radar screens, he said.
"We will need to study the black box to ascertain the exact cause of the crash. The (control) tower did not receive any SOS message or report of a technical problem before the crash," he said.
Sources in the Civil Aviation Authority expressed surprise at authorities clearing the aircraft to land at Islamabad despite the poor visibility and bad weather around the federal capital. The sources told PTI that state-run Pakistan International Airlines had diverted all its flights to Islamabad to Lahore.
Footage aired on TV news channels showed thick white smoke rising from the crash site. Witnesses said they had seen flames in the wreckage of the aircraft.
Authorities declared an emergency in all hospitals in Islamabad. Scores of anxious relatives of passengers gathered at the Benazir Bhutto International Airport to get information about their kin.
President Asif Ali Zardari and Prime Minister Yousuf Raza Gilani expressed shock and grief at the crash and directed authorities to take coordinated measures to reach the inaccessible site.
Image: Smoke rises from the wreckage of the plane | Photograph: Mian Khursheed/Reuters