ISLAMABAD, Pakistan (CNN) -- A commercial airplane carrying at least 121 people crashed Friday in Rawalpindi just before it was to land at an airport in Islamabad, according to Pakistan's Civil Aviation Authority, which cited poor weather as a possible factor.
The Bhoja Air Boeing 737 was making its first flight from Karachi to Islamabad, where the weather was cloudy, authority spokesman Pervaz George told CNN. Officials initially reported that 131 people were on board, but George later reduced that number.
There were no survivors, George said.
The crash occurred near the Pakistani air force's Chaklala airbase, which is adjacent to the Benazir Bhutto International Airport in Islamabad.
Debris and body parts were scattered across the crash site as workers sifted through the wreckage in the heavily populated residential area. At least 50 bodies had been recovered from the scene, a government official said Friday.
The Bhoja airliner was flying from the southern seaport city of Karachi and crashed just before touching down after its 3½-hour flight.
The crash site was about five aeronautical miles from the airport in Islamabad, authorities said.
Weather reports indicate conditions in the area included thunderstorms and limited visibility, according to CNN meteorologist Mari Ramos.
Authorities are investigating what may have caused the crash and the potential for additional casualties at the site of the wreckage. Rawalpindi is considered one of Pakistan's most populous cities.
Investigators are "going to be looking at technology," aviation security consultant Greg Feith said. "What kind of radio equipment, what kind of ground proximity warning system the aircraft was equipped with, weather radar, things like that ... since the weather may be a factor in this accident."
Pakistani Prime Minister Yusuf Raza Gilani on Friday expressed "deep shock and grief over the tragedy," ordering his country's Civil Aviation Authority "to gear up all its resources for rescue operation," state media reported.
A separate inquiry into the incident has been launched by Pakistan's Safety Investigation Board, and two crisis operation rooms have been set up at airports in both Islamabad and Karachi to provide accurate and timely information to affected families, reports said.
A Boeing spokeswoman, meanwhile, said the American manufacturer "stands ready to provide technical assistance to the Civil Aviation Authority of Pakistan."
"The Boeing Company wishes to extend its profound condolences to the families and friends of those lost today in the Bhoja Air accident in Pakistan, as well as wishes for the recovery of those injured," said Julie O'Donnell.
The crash is reminiscent of one In 2010,when 152 people were killed as a Pakistani passenger plane crashed on the outskirts of Islamabad, Pakistan's capital. That plane was also was coming from Karachi when it crashed into a hillside while trying to land, officials said at the time.
Four years earlier, another airliner crashed in central Pakistan, leaving 45 dead.
The first known commercial passenger airplane crash occurred in Pakistan in 1953 when a Canadian Pacific DH-106 Comet crashed shortly after takeoff from Karachi. That crash killed 11 people on board.