BERLIN - German police are questioning three British citizens after their conversation during a flight to London prompted an EasyJet pilot to make an unscheduled stop in Cologne late Saturday.

A spokesman for Cologne police says other passengers on the flight from the Slovenian capital Ljubljana overheard a conversation with “terrorist content” between the men, aged 31, 38 and 48.

Christoph Gilles told The Associated Press on Sunday that police destroyed a rucksack belonging to one of the men but found no explosives inside.

He said an investigation into whether the men were planning an attack was ongoing, but noted there might be an innocent explanation for their conversation.

Gilles said the remaining passengers, several of whom were slightly injured during the plane’s evacuation, would likely be flown to London later Sunday.