Islamabad, May 16 (IANS): The British authorities detained 14 crew members of a Pakistan International Airlines (PIA) flight and the aircraft was "thoroughly searched" over security threats after it landed at London's Heathrow Airport.

Flight PK-785 from Islamabad to London arrived at Heathrow Airport at 2.50 p.m. on Monday. Upon landing, as passengers disembarked, the flight crew and aircraft were searched by the authorities, PIA spokesperson Mashhood Tajwar.

Tne crew was released after two hours of interrogation pertaining to the security concerns, Geo News reported on Tuesday.

"We have not been informed as to why was the crew detained," said Tajwar. The crew members' passports were also taken away by the police, the report said.

According to the British Police, the crew was taken under custody over security concerns but was released later as nothing was found during the search operation.

PIA said it is seeking to protest against the British Police misconduct with the flight crew.

The flight, meanwhile, was later cleared to take off from Heathrow Airport with replaced crew members.