An EasyJet flight to London has made an unscheduled stop in Germany after the pilot became concerned about a suspicious conversation on board.

The plane coming from the Slovenian capital Ljubljana landed at Cologne-Bonn airport at about 6.30pm local time (4.30pm GMT) Saturday.

Airport authorities said in a statement that the 151 passengers on board disembarked the plane using emergency slides and were taken to a transit gate where they were checked by police.

German news agency dpa reports that police also destroyed a piece of baggage that couldn't be assigned to anybody on board.

Take-offs and landings were suspended for three hours, causing 10 flights to be diverted to other airports and delays to over a dozen more.