ISLAMABAD (AP) ― Pakistan on Saturday barred the head of the airline whose jet crashed near the capital from leaving the country, vowing to investigate a tragedy that has revived fears about the safety of aviation in a country saddled by massive economic problems.

The Bhoja Air passenger jet crashed Friday evening as it tried to land in a thunderstorm at Islamabad’s main airport, killing all 127 people on board. The second major air disaster close to the capital in less than two years, the crash triggered fresh criticism of an already embattled government, which faced questions over why it gave a license to the tiny airline just last month.

Sobbing relatives of those who died flocked to a hospital in Islamabad to collect the remains of their loved ones.

“We had no idea they would be called for eternal rest,’’ said Sardar Aftaz Khan, who was trying to secure the release of the bodies of her mother, an aunt and a nephew.

Speaking after visiting the scene of the crash, Interior Minister Rehman Malik said that Farooq Bhoja, the head of Bhoja Air, had been put on the “exit control list,’’ which bars him from leaving Pakistan. Such a ban is often put on someone suspected or implicated in a criminal case.

Malik said Bhoja had been ordered into protective custody and a criminal investigation launched into the crash, presumably running alongside the one being carried out by aviation authorities.

Prime Minister Yousuf Raza Gilani also ordered a third probe, known as a judicial commission, into the accident.

Nadeem Yousufzai, the head of the Civil Aviation Authority, urged people not to speculate on the cause of the crash before all the evidence had been collected.

He said he had listened to a recording of the conversation between the pilot and the control tower and said the pilot was in a “happy’’ mood. He said the weather was bad, but noted that another plane landed safely at the airport five minutes after the crash.

He denied there was any “political pressure’’ in the awarding of the license to Bhoja Air, one of just three private airlines in Pakistan. The airline only recently received a permit and began flying last month after it lost its license in 2001 because of financial difficulties.

A representative for Bhoja Air, Jahanzeb Khan, declined comment on the travel ban against Farooq Bhoja and said the airline would discuss the case after the investigation was complete.

Malik, the interior minister, appeared to back up theories aired by some in the media that the age of the aircraft may have been a factor, saying the airline “seems to be at fault as it had acquired a very old aircraft.’’

“If the airline management doesn’t have enough money it doesn’t mean you go and buy a 30-year-old or more aircraft as if it were a rickshaw and start an airline,’’ he said.

According to the Web site www.airfleets.net, the Bhoja jet was 32 years old and first saw service with British Airways in South Africa.

Thirty-two years is not especially old for an aircraft, and age by itself is rarely an important factor in crashes, said Nasim Ahmed, a former crash investigator.

Malik’s comments ― and the three official investigations ― appeared to be part of a government effort to move quickly and deflect some of the criticism that it is likely to find itself under in coming days because of the crash.

Such is distrust of the state in Pakistan, few believe the government ― which lurches from crisis to crisis, clinging to power in the face of a mostly hostile media, opposition and judiciary ― has the will to hold politically connected people accountable or carry out credible investigations.

The violent storm that was lashing Islamabad when the accident took place has led some experts to speculate that “wind shear,” sudden changes in wind that can lift or smash an aircraft into the ground during landing, may have been a factor. It may even have been a dangerous localized form of the phenomena, called a microburst. That can cause planes to lose airspeed suddenly or lift abruptly if a headwind suddenly changes to a tail wind during takeoff or landing.

Soldiers and emergency workers at first light began the grim task of looking for bodies and body parts among the debris from the Boeing 737-200, which was spread out over a one-kilometer stretch of wheat farms around five kilometers (three miles) from Benazir Bhutto International Airport.

The plane was flying from the southern city of Karachi to Islamabad when it crashed.

One soldier had a plastic bag over his hand and was picking up small bits of flesh. Another was using a stick to get at remains in a tree.

“We are collecting these so that the souls are not desecrated,” one of them said.

The officers were also picking up personal effects of the passengers, making piles of documents, bank cards, gold and bangles.

The last major plane crash in the country ― and Pakistan’s worst ― occurred in July 2010 when an Airbus A321 aircraft operated by domestic carrier Airblue crashed into the hills overlooking Islamabad, killing all 152 people aboard. A government investigation blamed the pilot for veering off course amid stormy weather.

Nasim Ahmed, the former investigator, said it appeared at this stage that the age and air worthiness of the plane were unlikely causes.

He said that a combination of factors during landing was probably to blame, possibly the weather or some form of unexpected incident that caused the pilot to lose vital awareness of the plane’s location.

Ahmed said the accident highlighted long-standing weaknesses in Pakistan’s aviation industry, which he said couldn’t be separated from management problems in the Civil Aviation Authority, poor government oversight and corruption and nepotism in the state-owned Pakistan International Airlines.

In 2007, the European Union banned most PIA flights from its member’s airports for eight months due to safety concerns.