A six-hour search of the plane's cabin and the 300 passengers' luggage revealed nothing suspicious, police said. The aircraft was allowed to take off at 12.45pm. "The plane has now been thoroughly searched, and police are satisfied there is no threat to safety," an Essex police spokesman said.
Police said "well-rehearsed procedures" had immediately been followed after an anonymous call to a Greek newspaper yesterday alerted authorities to the possibility that a bomb was on board Olympic Airways flight 411 from Athens to New York JFK.
Passengers and crew were safely evacuated within 20 minutes of the flight's arrival at Stansted, in Essex, where it had been diverted, escorted by fighter jets.
Since the September 11 2001 terror attacks on New York and Washington, it has been normal procedure for threatened planes to be accompanied into Stansted - the UK's designated hijack airport - by RAF fighter jets.
The alert came after the Greek newspaper Ethnos received the anonymous warning call. According to a tape made available to journalists by the newspaper, the caller said: "Flight 411 Olympic for America has a bomb for Iraq."
In a second call, a voice sounding like another person said: "Are you listening? Flight 411 Olympic for America - bomb. America will see. Six o'clock message for you." Authorities immediately notified the pilot, who asked for a military escort.
Chief Inspector Peter French, of Essex police, said a criminal investigation had been launched to track down whoever was responsible for making the bomb threat. He said Essex officers had been in overnight contact with the Greek authorities in an attempt to identify the hoaxer.
"We are treating this as a criminal act, and a criminal inquiry has been launched to bring whoever is responsible to justice," Chief Inspector French said. "I am sure the justice system will come down hard on any individual found to be responsible for this kind of action."
He praised the passengers for the way in which they had coped with the situation, adding: "We had 300 passengers destined for New York - and then all of a sudden they are going to the unknown destination of Stansted. Under the circumstances, the passengers reacted extremely well."
He said that, despite the threat having turned out to be a hoax, he had no doubt it had been right to land the plane so thorough checks could be carried out. "We will deal seriously with any incident that occurs, and we will be thorough in the way we deal with it," he said.
