Britain today scrambled its fighter jets after a mid-air "security alert" on board a Manchester- bound Pakistan International Airlines flight and diverted it to a designated counter-terrorism airport in northeast London.
Two Royal Air Force (RAF) fighters were deployed alongside the Boeing 777 to intercept the plane travelling from Lahore, reports said.
The reports said the aircraft has now landed in Stansted, Britain's designated counter-terrorism airport.
"Typhoon aircraft from RAF Coningsby were launched today to investigate an incident involving a civilian aircraft within UK airspace; further details will be provided when known," a Ministry of Defence spokesperson said.
Essex Police said its officers are responding after "an incident" occurred on Flight PK 709.
"An incident has occurred on an aircraft. Police and partners are responding," the spokesperson said.
There are understood to be 297 passengers on board travelling from Lahore to the UK.
The plane was heading west towards Manchester when it was suddenly re-routed near York and headed back out to the North Sea, before travelling south to Stansted.
The airline has confirmed the diversion was for security reasons and the speculation so far is that it is a precautionary measure in response to an emergency signal.
