LONDON (CNN) -- Police arrested two men Friday on suspicion of endangering an aircraft after a flight from Pakistan to the United Kingdom was diverted to Stansted Airport, outside of London.
A UK fighter jet was scrambled to escort Pakistan International Airlines Flight PK709 from Lahore as it was diverted from northwestern England's Manchester Airport to Stansted.
Essex Police, who cover the area near Stansted airport, said officers had arrested the men and removed them from the plane, which had 297 passengers aboard.
Police declined to release the identities of the two men, saying only they are British nationals ages 30 and 41.
Police said the incident is being treated as a criminal offense, and did not mention a terrorism angle.
Wajid Hasan, Pakistan's High Commissioner to the United Kingdom, told CNN that the two passengers "got into an altercation with air stewardesses and threatened to blow up the plane."
The flight attendants contacted the pilot, who contacted UK air traffic control authorities, who then scrambled the fighter jets, he said.
"So far nothing has been found," he said. "All the passengers are off the aircraft and are being screened, as would be normal, by immigration authorities," he said, and the cargo is also being searched.
The process is expected to take about four hours, he said, after which the passengers will fly on to Manchester.
The commission has sent officials to Stansted Airport to provide consular assistance to passengers who need it, a written statement said.
Pakistan International Airlines spokesman Mashood Tajwar said the aircraft would then fly from Manchester to Lahore, Pakistan.
Passengers arriving at Stansted told CNN they were delayed by what several called a "terrorist scare."
A top official with Pakistan International Airlines earlier said the diversion was prompted by an unruly passenger.
"The passenger was simply causing a disturbance on the plane and threatening passengers and staff. This is a lesson to angry passengers," the official said.
Tajwar told CNN that the plane was 20 minutes away from Manchester Airport and preparing to land when air traffic controllers there received reports of a "terror threat."
British police had not yet been in touch with the airline to confirm if this was actually a terror threat related to passengers on board the PIA flight, Tajwar said.
"This information may be a bomb threat but we are not sure yet, it could be a fake threat," Tajwar told CNN.
A security source in London told CNN that early indications suggested the diversion of the flight to Stansted Airport was not a terror-related incident.
A representative for Stansted Airport said the plane was on an isolated stand away from the normal airport and police were handling the situation.
Typhoon aircraft were launched from RAF Coningsby to investigate the incident, the UK Defense Ministry said.
The Boeing 777 landed at 2:10 p.m. (9:10 a.m. ET).