A Ryanair flight from Krakow to Dublin was diverted to Stansted Airport on Monday night after a note claiming there were explosives on board was found in the lavatory.
Two Typhoon fighter jets from RAF Coningsby, Lincs, were scrambled to escort the plane to the Essex airport shortly before 6.30pm.
Essex Police confirmed all passengers were safe and had disembarked the aircraft last night, adding: "The plane remains in an isolated area at Stansted and our inquiries are ongoing."
A Ryanair spokesman said the captain had followed procedure by alerting the UK authorities and diverting to the nearest airport.
The plane landed normally, but was taxied to a remote stand at the airport where passengers disembarked safely, they added. The aircraft and passengers were subsequently examined by police.
"A Ryanair flight from Krakow to Dublin this evening discovered a note in one of the toilets claiming that there were explosives on board," the spokesman said.
"Ryanair apologises sincerely for the delay and inconvenience caused to those affected by this diversion."