RAF jets caused a sonic boom as they scrambled to escort a flight into Heathrow Airport after a pilot reported a bomb threat.
Two RAF Typhoon jets rushed to intercept Air India flight AC129, which had been due to land at Heathrow at 12.05pm.
The flight, from Mumbai, was forced into a holding pattern prior to landing at the London airport this afternoon.
A Royal Air Force spokesperson said: "We can confirm that RAF Quick Reaction Alert Typhoon fighter aircraft from RAF Coningsby were launched this afternoon, to investigate a civilian aircraft.
"Following an uneventful interception the aircraft was released to continue to its original destination under the direction of civilian air traffic control.
"This incident is now being handled under the control of civilian authorities."
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Norfolk Police also confirmed the RAF jets had caused a sonic boom.
A statement added: "Police can confirm a loud noise heard by residents in the county was a sonic boom caused by RAF aircraft this afternoon and was not an explosion.
The Boeing 77's pilot is understood to have reported that a suspected bomb was on board the flight.
It comes as more than a dozen bomb threats have been made against Indian flights this week.
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The threats have forced the government and Indian civil aviation authorities to warn of "very strict action".
A Vistara flight from Frankfurt to Mumbai - carrying more than 100 passengers - also issued a "security threat" earlier today, before landing safely as planned in India.
A subsequent statement from the airline said: "We are fully cooperating with the security agencies to complete the mandatory security checks."
Investigators are currently probing whether there is a "pattern" behind the bomb threats, The Independent reports.