A Ryanair flight was forced to make an emergency landing after a note warning explosives were on board was found in the toilets.
RAF Typhoon fighter jets were sent to intercept the aircraft travelling from Krakow to Dublin after the alert was raised on Monday evening.
After landing safely on the runway at London Stansted Airport, police oversaw the evacuation of the plane in an isolated area.
Essex Police described the incident only as a “security alert” and said officers were still investigating.
However Ryanair said that the diversion of the Boeing 737-800 was prompted by the discovery of “a note in one of the toilets claiming that there were explosives on board”.
“The captain followed procedure by alerting the UK authorities and diverted to the nearest airport where the plane landed normally, but was taxied to a remote stand where passengers disembarked safely,” a spokesperson for the airline said.
“The aircraft and passengers are being checked by the UK police who will decide when they may travel onwards to Dublin on a spare aircraft.
“Passengers in Dublin waiting to depart to Krakow are being transferred to a spare aircraft to minimise any delay to their flight.
“Ryanair apologises sincerely for the delay and inconvenience caused to those affected by this diversion”.
The Ministry of Defence confirmed that two Typhoons were dispatched from RAF Coningsby to “inspect” a Ryanair passenger flight. ”It was all escorted escorted safely and there were no issues after that point,” a spokesperson added.
Essex Police said in a statement at 9pm: “We have now safely brought off all the passengers from the plane. The plane remains in an isolated area at Stansted and our enquiries are ongoing.”