A passenger plane belonging to the private Airblue service was flying from the southern port city of Karachi when it crashed into the hills near the Pakistani capital while trying to land in rainy and cloudy conditions, killing all 152 passengers and crew on board.
Rescue teams were immediately dispatched to the site while army helicopters hovered over the Margalla Hills to look for survivors.
Television pictures showed wreckage from the plan and a thick blanket of clouds. Smoke caused by fire could be seen rising from the crash site.
Residents of Islamabad saw the plane flying very low just before it crashed.
The head of the National Disaster Management Authority, Nadeem Ahmad, said that the difficult terrain and weather were hampering the rescue efforts.
"I have been on the site and saw things very closely. To me, the chances of survivors are extremely difficult," Nadeem said. "But we have not been able to evacuate any of the people so far because, one, we are stuck with the bad weather, second, the area has absolutely no access, it is all ridge line which as about 90-degree gradient and there is no access track and road."
Authorities say it will be premature to discuss the causes of the crash without proper investigation.
Airblue spokesman Raheel Ahmed said he suspects weather conditions might have caused the crash. Ahmed said the plane had no known technical problems and the pilots had not sent any emergency signals.
"It was a (Airbus) 321 aircraft, not very old, about eight to 10 years old and in the aviation, this thing is not very old. Maintenance was done regularly, like I said, there was nothing wrong technically with the aircraft," Ahmed said. "Of course when the investigation will take place they will get to know what all happened, but right now I do not think we should get into speculations as such."
He added this was the first crash for the private Airblue service, which began operations in 2004. It is the second largest airline service in the country after the state-run Pakistan International Airlines, PIA.
In 2006, A passenger plane belonging to the PIA crashed near the central city of Multan, killing 45 people on board.