A Ryanair Boeing 737 has made an emergency landing at Stansted Airport after a suspected hoax security alert.
Flights from the airport were temporarily grounded at the airport, just outside London.
The plane was diverted from its route between Kaunas, Lithuania, and Luton airport in Bedfordshire.
Stansted is the designated UK airport for security situations of this nature.
The plane was escorted to the airport by two RAF fighter jets.
Ryanair said the plane was diverted after Lithuanian authorities received what is now believed to be a hoax threat.
A Ryanair spokesman said: “The 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.”
Essex police have confirmed they are now dealing with the incident.
An RAF spokesman confirmed two jets were scrambled from RAF Coningsby in Lincolnshire.
The planes were authorised to travel at supersonic speed, which is only permitted overland in emergency situations.