Three British men were detained after their conversations prompted an easyJet flight to divert to Cologne Germany.
The Airbus A319 flying from the Slovenian capital Ljubljana was diverted after passengers reported that the men were talking about “terrorist matters”, police and state prosecutors said in a joint statement.
The individuals have since been detained by German authorities and are undergoing questioning. Authorities said none of them was previously known to security services.
The diversion to Germany’s Cologne-Bonn airport on Saturday caused a major police operation and hours of air traffic chaos. On Sunday, a police spokesman said it was unclear if any charges would be brought against the men.
No explosives were found in the detainees’ luggage or on the plane and a spokeswoman for the airport said the remaining passengers were scheduled to fly on to London around 1100 GMT.
Nine people received medical treatment after all 151 passengers were evacuated from the aircraft using emergency slides.
Bild newspaper quoted a spokesman for the German federal police as saying the pilot decided to land the aircraft in Cologne after passengers told airline personnel they had heard the men using words including “bomb” and “explosive”.
The men were aged 31, 38 and 48, a spokesman for Cologne police said.
Bild newspaper said the men worked for a London company and were returning to London after a business trip.
A backpack that belonged to the men was examined and destroyed in a controlled explosion by authorities but no dangerous contents or explosives were found in the bag or on board the aircraft, a police spokesman said.
Police and prosecutors had said they were investigating a suspicion that the men were preparing to carry out, “a serious violent crime that could have jeopardized the state”.
The airport spokeswoman said air traffic had returned to normal after a three-hour interruption on Saturday evening. Seventeen arriving flights were diverted to other airports, 20 departing flights were significantly delayed and two flights were canceled, the airport said.
No additional passengers were detained, the police spokesman said.