UPDATED BREAKING NEWS: RAF Coningsby jets scrambled to help with Pakistani passenger plane incident - two arrests made

The aircraft was a Pakistani passenger plane which had been diverted from Manchester to Stansted Airport.

The Pakistan International Airlines jet accompanied by fighter jets landed at Stansted where two men were arrested

A Pakistan International Airlines spokesman Zufiqar Bijarani told CNN: “We have been told there may have been a bomb threat.” But he did not say if he had anything to confirm or deny this.

An MoD spokesman said the incident was now a police matter and that “our involvement is over”.

He said Typhoon jets could be scrambled after the pilot or crew of a passenger aircraft sends out an emergency signal.

“The purpose of going up is to investigate what the situation is,” he said.

“Often when a Quick Reaction Alert aircraft is launched the details are not known, but it is known that a signal has been sent.

“Part of the purpose of sending a Typhoon up is to have a look and see what they can see.”

Reports say the plane’s transponder track shows it got near to Leeds then diverted back over the North Sea and down to Stansted, the usual place for security threats.

The RAF jet was scrambled following an incident around 10 minutes before the plane, which departed from Lahore, was due to land in Manchester at 2pm today.

The incident is not thought to be terrorism-related at this stage, it is understood.

A spokesman for the Aviation Security International,said: “This is certainly a significant incident, however the fact that fighter jets were scrambled to intercept is not unusual.

“Fighter jets are scrambled when there is a bomb threat, when there is a hijack, when the wrong transponder code is used or if an aircraft cannot communicate with the ground. Often the result is when there is an unruly passenger on board.

“What is interesting in this case is that it would appear that the aircraft was only 10 minutes from landing - these are initial reports coming in - when they decided to divert to Stansted. So to actually change a destination 10 minutes from landing would certainly imply that there was some serious incident taking place.”