A Pakistani airliner with 127 people on board crashed in bad weather as it came in to land in Islamabad on Friday, scattering wreckage and leaving no sign of survivors.
The Boeing 737, operated by local airline Bhoja Air, was flying to the capital from Pakistan's biggest city and business hub Karachi. It crashed more than five miles (nine km) from the international airport.
Aviation official Pervez George gave no details of casualties.
But rescue workers at the crash site said there was no chance of finding survivors.
Residents said they had seen a ball of fire in the sky when the plane crashed. Parts of the plane smashed into electricity poles, blanketing the area in darkness.
Officials gave no immediate indication as to why they thought the plane had crashed.
A man who had been waiting at Islamabad's Benazir Bhutto International Airport for the flight yelled "my two daughters are dead" as tears streamed down his face.
In a state of shock, he then slumped on the floor and sat silently as other relatives of passengers crowded around lists of those on board.
The uncle of the sisters said they were supposed to return to Islamabad on Sunday but flew early to see an aunt who is visiting from London.
"We don't even know when or where we will get to see their bodies," said the uncle, Qamar Abbas, who kept mumbling "no, no, no" to himself.
Nearby, relatives of passengers hugged each other and sobbed. One man cried "my kids, my kids."
Among them was Zarina Bibi, desperate to determine whether her husband was on the flight. "He called me before leaving Karachi but I don't know if he was on this flight or not," said Bibi, whose eyes were red from crying.
State television reported that all hospitals in Islamabad and the nearby city of Rawalpindi had been put on high alert after the crash.
The last major aviation accident in Pakistan was in July 2010, when a commercial airliner operated by AirBlue with 152 people on board crashed into the hills overlooking Islamabad.
In 2006, a Pakistan International Airlines aircraft crashed near the central city of Multan, killing 45 people.
(Additional reporting by Qasim Nauman, Rebecca Conway and Rehan Sheikh in ISLAMABAD and Sahar Ahmed in KARACHI)