ISLAMABAD: Pakistan on Thursday mourned the 47 victims of its deadliest plane crash in four years, including a famed rock star-turned-Muslim evangelist, as officials sought to pinpoint the cause of the disaster.

Engine trouble was initially believed responsible, but many questions remain, stirring new worries about the safety record of money-losing state carrier Pakistani International Airlines.

The ATR-42 aircraft involved in the crash had undergone regular maintenance, including an "A-check" certification in October, said airline chairman Muhammad Azam Saigol.

"I want to make it clear that it was a perfectly sound aircraft," Saigol said.

The aircraft appeared to have suffered a failure in one of its two turboprop engines just before the crash, he added, but this would have to be confirmed by an investigation.

"I think there was no technical error or human error," Saigol told a news conference late on Wednesday. "Obviously there will be a proper investigation."

Grief erupted online soon after flight PK661 smashed into the side of a mountain near the town of Havelian, in Khyber-Pakhtunkhwa province, on Wednesday, after taking off from the mountain resort region of Chitral.

It crashed just 50 km (31 miles) short of its destination, the international airport in Islamabad, the capital.

A PIA spokesman said the pilot, who issued a "mayday" emergency call before the crash, may have prevented an even bigger catastrophe by manoeuvring the plane away from populated areas.

"It seems that the pilot directed it away from people's homes. Otherwise there could have been even more damage," Daniyal Gillani told Reuters outside a morgue at an Islamabad hospital where bodies were being identified.

Stunned relatives gathered there, some weeping quietly, others besieging officials with questions.

"What can I tell you?" said Raja Amir, as he waited for his mother's remains. "I don't know what we will get of her. There is still another hell to go through."

Remains continue to be brought by helicopter to Islamabad, where DNA tests will be used to identify them.

Television images appeared to show rescue officials retrieving the aircraft's "black box" flight recorder from the wreckage, and the airline confirmed the recovery to the Geo News channel.

ROCK STAR AND ROYALTY

Much of the public's anguish focused on Junaid Jamshed, the vocalist of Vital Signs, one of Pakistan's first and most successful bands of the 1990s, who abandoned his music career in 2001 to become a travelling evangelist with the conservative Tableeghi Jamaat group.

Many comments on social network Twitter pointed up the contrast between his two roles, first as a pop sensation singing about love and heartbreak, and then as a stern, bearded preacher admonishing young people for straying from Islam.

"Junaid Jamshed's journey was so quintessentially Pakistani. Conflicted, passionate, devoted, ubersmart, and so, so talented. Tragic loss," Mosharraf Zaidi, an Islamabad-based development professional and analyst, said in a tweet.

Others simply shared his band's many hits, such as 'Dil Dil Pakistan', which has become an unofficial anthem, played at public gatherings since its release in 1987.

Among the 46 others who perished were two infants, three foreigners - two Austrians and a Chinese man - and five crew listed on the manifest.

Foreign tourists increasingly travel to Chitral, along with numerous domestic visitors, as Pakistan emerges from years of militant violence.

The dead included a member of Chitral's traditional royal family, his wife and family, besides a regional administrative official, Osama Ahmad Warraich, killed with his wife and infant daughter.

At a funeral for the Warraich family, Osama's mother was seen waving at the coffins and weeping: "Let me say goodbye to my kids one more time".

SAFETY CONCERNS

The aircraft, made by French company ATR in 2007, had racked up 18,739 flight hours since joining PIA's fleet that year.

Its captain, Saleh Janjua, had logged more than 12,000 flight hours over his career, the airline said.

Concern is growing over air safety as media in recent years have reported several near-misses.

In the worst disaster, in 2010, all 152 people on board were killed when a plane operated by airline Air Blue crashed in heavy rain near Islamabad.

Two years later, all 127 aboard were killed when a plane operated by Bhoja Air crashed near the city.

The father of one of the crew who died lashed out at PIA and the government, saying better management could have prevented the crash.

"I have no hope," Raja Abdul Ghaffar said after the body of his son was brought to the morgue. "I am left with nothing."