German officials say they have uncovered a terrorist plot to blow up a passenger plane in Germany.
Few details have been released about the alleged bomb plot
German police questioned six suspects on Friday over the alleged plot, but five were released on Saturday, the federal prosecutor's office said.
Several suspects allegedly approached a contact in the summer who had special access to a restricted airport zone.
The plan was to plant explosives in a piece of luggage, investigators said, without giving further details.
One of those arrested on Friday remains in custody in connection with another investigation, the officials said.
Nine apartments were searched on Friday in Rhineland-Palatinate state and Hessen, they added.