LONDON -- British police arrested two men aboard a diverted Pakistani airliner on Friday after Britain's Royal Air Force scrambled Typhoon fighter jets to escort the airplane flying from Lahore to Manchester, in the north of England, according to defense ministry officials and the police.
A spokesman for Pakistan International Airlines said the two men had threatened to blow the plane up, then said they were joking.
Airport authorities in Manchester said the Pakistan International Airlines plane, with more than 300 people on board, had been due to land there but had been diverted to Stansted, just north of London, where it landed and taxied to a remote area.
The police at Stansted said that officers then boarded the plane and arrested two men ages 30 and 41 "on suspicion of endangerment of an aircraft."
The spokesman for P.I.A., Mashhud Tajwar, said that shortly before the plane was to land in Manchester the men threatened a flight attendant that "they will blow the plane up," which was reported to the pilot. The pilot consulted air traffic control at Manchester and was diverted to Stansted. "Later," Mr. Tajwar said, "the two passengers said they were joking. But the security procedure has to be followed."
He said both men were British citizens.
A Pakistani Defense Ministry spokeswoman, Nareeta Farhan, said that initial reports indicated that the two men were arguing when one of them "repeated twice or thrice that he will blow up the plane."
Deployment of warplanes is a standard procedure, according to defense ministry officials, when pilots using emergency codes raise the alarm. The Typhoons took off from an air base at Coningsby in Lincolnshire.
An official who spoke in return for anonymity under ministry rules said such deployments "happen more often than we would think. It's standard procedure in situations when, for example, contact with the pilots and the plane is lost."
Pakistan International Airlines said the airplane -- flight number PK709 -- with 308 passengers and 14 crew members, had taken off after customary security checks in Lahore and was heading to Manchester when, shortly before it was scheduled to land, British airport officials told the pilot to divert to Stansted, a sprawling airport in rural Essex which is officially designated as suitable for dealing with emergencies.
The diversion of the plane came two days after two assailants hacked to death an off-duty British soldier on a busy street in London, but there was no suggestion that the two episodes were linked.
Earlier on Friday, a British Airways jet made an emergency landing at Heathrow Airport in London after developing engine trouble on takeoff. The plane, bound for Oslo with almost 80 people on board, landed safely and was evacuated.
Julia Werdigier contributed reporting from London and Salman Masood from Islamabad.
Correction: May 24, 2013, Friday
This article has been revised to reflect the following correction: An earlier version of this article misstated the timing of the plane's diversion. It came two days after an off-duty British soldier was killed in London, not one day after.world
This article originally appeared in The New York Times.