Two Russian men, both pilots, were taken into custody Wednesday at Berlin's Tegel Airport after a witness told police she suspected they were planning a hijacking, authorities said.
The two men, aged 49 and 26, were booked on an Air Berlin flight to Moscow around midday, federal police spokeswoman Sandra Pfeifer said. Though they were both registered pilots, neither was part of the aircraft's crew, she said.
They were overheard speaking in Russian by a woman at an Air Berlin counter before they boarded the plane, said Berlin police spokesman Michael Gassen.
"She had the impression that a hijacking of the plane to Moscow was planned," he said without elaborating.
Pfeifer confirmed that the two men were taken into custody after a conversation was reported, but would also not say specifically what the two men are alleged to have said.
The two were taken into custody by federal police, Pfeifer said. They had gone through security checks already by the time they were apprehended and were not armed, she added.
Both have been turned over to Berlin police for questioning.
The plane was evacuated and its 135 passengers were all questioned. Most were able to take a later flight to Moscow, police said.
Hans-Christoph Noack, a spokesman for Air Berlin confirmed that two men, who were licensed pilots, had been arrested. Noack said Air Berlin was cooperating with authorities investigation.
He was unable to give any further details regarding the witness.
AP writers David Rising and Melissa Eddy contributed to this report.