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 into wheat fields more than 5 miles from the airport.
Rawal Khan Maitla, director general of Emergency Disaster Management for the Capital Development Authority, said there were no survivors.
Rescue workers walked through mud at the crash site with flashlights or with the lights of their cellphones looking for passengers' remains. One held up a tattered e-ticket receipt.
Body parts, wallets and eyeglasses lay among wreckage strewn in a small settlement just outside Islamabad.
"It was as if the entire sky had burst into flames," said a resident of the area.
Parts of the aircraft smashed into electricity poles, blanketing the area in darkness, or into houses. There were no reports of casualties on the ground.
Bhoja Air said the airplane crashed during its approach in Islamabad due to bad weather. There was no indication from the government that it could have been the result of foul play.
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, 18 and 20, 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.
HEADED FOR HONEYMOON
When Sajjad Rizvi and Sania Abbas boarded the flight, they were looking forward to their honeymoon in a hill resort near Islamabad. "We had a joint wedding on March 28," said Sania's brother Zeeshan at the airport.
Nearby, relatives of passengers hugged each other and sobbed. One man cried "my kids, my kids".
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.
State television reported that all hospitals in Islamabad and the nearby city of Rawalpindi had been put on high alert after Friday's crash.
At the capital's main hospital, rescue workers brought in remains of the passengers placed under white sheets soaked in blood.
"Two years later the same story is being repeated in my house again," said Nasreen Mubasher, who was at the hospital waiting for the remains of her brother-in-law, who was a passenger. Another brother-in-law died in the AirBlue crash.
As the police struggled to keep order, trying to keep the distraught calm and television cameras away, Mohammad Nasir hoped somehow that his brother's body would be intact despite the horrific force of the crash.
He approached other relatives of passengers and hospital workers. He kept asking "have you seen any whole bodies?"
The Boeing Company said in a statement on its website that it "wishes to extend its profound condolences to the families and friends" of the Bhoja Air passengers.
At Karachi airport, Asim Hashmi complained the airline's counter was shut and he had no way of obtaining information on his aunt and cousin, who were on flight B4-213.
"We don't know anything," he said. "Just pray for the souls of the departed. That is all we can do now."