A plane with more than 150 people on board has crashed in hills north of the Pakistani capital, Islamabad.

Officials said 20 bodies had been recovered and at least three injured people had been taken to hospital.

Police said it was an Airblue flight from Karachi to Islamabad.

The plane came down in the Margalla Hills north of the capital, and Pakistani TV showed images of smouldering wreckage on a foggy hillside, with helicopters overhead.

Thick plumes of smoke can be seen rising from the Margalla Hills that overlook the Pakistani capital.

Weather conditions in recent days have meant many flights have been cancelled, though this one was allowed to fly from Karachi, on what is a very popular route.

The skies here are heavily overcast, and at the time of the crash there was also a heavy monsoon rain and thick fog.

A huge rescue effort has been launched.

The plane, reported to be an Airbus A321 with 146 passengers and six crew on board, is thought to have left Karachi at 0750 (0350 GMT).

Officials said the plane, believed to be flight 202, lost contact with the control tower minutes before landing.

An Express 24/7 television journalist at the scene of the crash said he had seen 15 bodies.

"They are badly mutilated and burnt," Sabur Ali Sayed said, "and there are two women are among the dead."

He added: "A good number of rescue workers have reached the site. Other people have reached here on their own. The plane is totally destroyed. The pieces and parts scattered over a large distance. Some parts of the plane are still burning. Some bushes have been burnt."

Officials said forestry guards in the Margalla Hills searching for survivors had seen five bodies.

Airblue spokesman Raheel Ahmed told reporters that the crash was "an extremely tragic incident".

"Our first priority is to find the survivors. The weather is not conducive for rescue but rescue teams have reached the spot," he said.

 Anjum Rahman, a journalist with Express 24/7 television in Islamabad, said she saw the plane flying over the rooftops of houses where she lives.

"I wondered why the plane wasn't flying higher as it was flying towards the hill. Then within three or four minutes I heard a loud explosion," she told the channel.

Witness Khadim Hussain told the Reuters news agency: "It was raining. I saw the plane flying very low from the window of my office."

Saqlain Altaf told Pakistan's ARY news channel that he was on a family outing in the hills when he saw the plane, looking unsteady in the air.

"The plane had lost balance, and then we saw it going down," he said, adding that he heard the crash.

Mohammed Usman, an official at the Benazir Bhutto International Airport, said dozens of relatives of passengers gathered there were crying and desperate to get information about their loved ones.

Initial reports said the flight originated in Turkey, but this has not been confirmed. Later reports suggested it was a commuter flight.