Bavaria's state criminal police office said seven properties in the southeastern German region and three other states were searched.
The raids were prompted by investigations into 23 emails sent to recipients across Germany over a two-week period in July that contained threats of bomb attacks, among other things. The authors signed off as "People's Front," ''Combat 18" or "Blood and Honor."
Seven people are under investigation and six of them were temporarily detained Wednesday morning, according to Bavaria's state interior minister, Joachim Herrmann.
They were released once the raids were over. Authorities weren't immediately able to locate the seventh suspect.
Herrmann said authorities will now carefully evaluate evidence that was seized.
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