A security scare on board a Ryanair flight that was escorted by RAF jets and saw flights at Stansted Airport grounded was a suspected hoax, the airline said.
Passengers were evacuated after the plane was diverted from its route between Kaunas, Lithuania, and Luton Airport in Bedfordshire, and forced to land at Stansted, Essex, at around 8.55am on Wednesday.
Social media users posted pictures of armed police at the scene and the RAF Typhoon jets following the aircraft through the air.
Essex Police said officers found nothing suspicious on board.
A Ryanair spokesman said: "This flight from Kaunas to London Luton diverted to London Stansted in line with procedures after Lithuanian authorities received a suspected hoax security alert.
"The aircraft landed normally at Stansted and customers will be transferred to Luton by coach when cleared to do so."
A spokesman for the airport said all flights had now resumed after being held for about 10 minutes.
One passenger, Jonathan Zulberg, said the flight had been delayed for up to 40 minutes in Lithuania.
"When we were allowed to board we saw fire engines and a police car but weren't told anything and we took off," he said.
He said a stewardess told him there had been a bomb threat made in Lithuania but other passengers learned that only when the captain made an announcement after the plane had landed in Britain.
He said: "First (the) pilot told us of diversion. Then only once landed after about 5-10 mins pilot made announcement of bomb threat.
"When I heard I was pretty surprised the plane was allowed to take off."
The RAF Typhoon jets were sent from RAF Coningsby, Lincolnshire, to intercept the aircraft, the Ministry of Defence said.
A sonic boom echoed across the Suffolk skyline when the jets sped through the sound barrier, Suffolk Police confirmed.
An RAF spokesman said: "The RAF can confirm Quick Reaction Alert Typhoon aircraft were launched this morning from RAF Coningsby to intercept a civilian aircraft.
"The aircraft was safely escorted to Stansted Airport. The Typhoon aircraft were authorised to transit at supersonic speed for operational reasons; any inconvenience caused to local residents is regretted."
Stansted is a designated airport for dealing with hijacks and major security alerts.