Reports from Pakistan say the 127 people who were on board a plane that crashed near the capital, Islamabad, are feared dead.
Officials said the Boeing 737 was flying from the southern city of Karachi to Islamabad when it went down in bad weather a few kilometers away from the Benazir Bhutto International Airport.
Reports suggest the plane was making its final approach to the airport when the crash happened at a location believed to be the village of Hussain Abad.
There were conflicting reports about how many people were on board the plane.
Severe thunderstorms were reported in the area at the time of the accident, but a spokesman for Bhoja Air, the flight's operator, refused to comment on the possible cause of the crash.
"I can't talk about the cause. The pilot was very good," he said. "He had more than 30 years of experience."
Emergency service officials said fire erupted after the crash. RFE/RL's Radio Mashaal quoted local reports as saying at least 10 houses were burning.
Television channels showed wreckage and charred parts of the aircraft as passengers' belongings lay strewn on the ground.
There was no immediate report of survivors or the number of casualties.
But Defense Minister Chaudhry Ahmed Mukhtar quoted civil-aviation officials as saying it was unlikely anybody had survived.
Islamabad police chief Bani Yameen, however, said that nobody on the ground appeared to be killed.
Officials said army rescue teams with ambulances and special equipment had been dispatched to the scene.
But helicopters reportedly had to turn back due to bad weather.
State television reported that all hospitals in Islamabad and nearby Rawalpindi were put on alert.
Reports say Bhoja Airline is a small commercial airline that ceased operations in 2000 because of financial difficulties and was reopened last year.
Pakistan's air industry has been booming and critics say standards have not always kept pace with the increase in activity.
The last major aviation accident in Pakistan occurred in July 2010, when an Airbus A321 operated by AirBlue crashed into the hills overlooking Islamabad, killing all 152 people on board.
Based on reporting by Reuters, AFP, AP, dpa, and RFE/RL's Radio Mashaal