The pilot of an aircraft carrying Pakistan's military ruler General Pervez Musharraf on the night he took power last October has been describing events on the day of the coup.

He was speaking at the trial of the ousted Prime Minister, Nawaz Sharif, who has been accused of preventing the plane from landing thereby endangering the lives of Gen Musharraf and nearly 200 other passengers.

Captain Syed Sarwat said he was told at first by Karachi air traffic control that he could not land there or anywhere else in Pakistan.

He said he only had 80 minutes of fuel at the time and feared it could run out.

"I have 198 souls on board and a limited amount of fuel," Captain Sarwat said he told the Karachi control tower.

"If I'm not allowed to land that will be the end of the story," he said.

The flight was returning to Karachi from the Sri Lankan capital, Colombo.

Captain Sarwat said he did not know that General Musharraf had been fired from his position as the head of the military.

"I felt very helpless. It was a very tense situation," he told the court.

He said he was later informed that he could land at Karachi for refuelling, but by then had lost confidence in the air traffic controllers because of the confusion.

He said he decided to land at Karachi when an army general told him from the control tower that it was safe to do so.

Mr Sharif's defence lawyers have been arguing that he only tried to stop the plane landing after the coup had been launched.

Army secures airport

On Wednesday, an air traffic controller at the airport described how he was ordered by the government to put all international flights on hold and block the runway to prevent the plane from landing.

The controller, Nadeem Akbar, said he assumed the order was linked to a possible hijacking.

He said the plane only touched down after a senior army officer entered the control tower and assured the pilot it was safe to land.

Mr Akbar said the army officer, General Iftikhar Ali Khan, had said the army had taken over.

He quoted the officer as saying: "The corps commander is with me and you can return to Karachi."

Another prosecution witness, Saeed Aqueel Ahmed, said he was told to divert the aircraft and prevent it from landing in Karachi.

The orders allegedly came from the head of Pakistan's Civil Aviation Authority, Aminullah Chaudhry.

Mr Chaudhry was originally accused in the case but agreed to give evidence in exchange for a pardon, and has become the prosecution's star witness.

Mr Sharif, his brother, Shahbaz, and five others have been charged with abduction, attempted murder, hijacking and terrorism.

All have pleaded not guilty. If convicted of the hijacking charge, they face the death penalty.

Mr Sharif has been in detention since he was overthrown in the coup.