Several regional courts in Germany received bomb threats through emails prompting evacuation on Friday, media reports say.
Similar warnings issued earlier had proved to be hoax. However, German police did not want to take any chances and they immediately secured the premises of courts in Potsdam, Magdeburg, Erfurt, Wiesbaden and Kiel, Hannoversche Allgemeine Zeitung newspaper said.
The threats issued through emails vowed attacks on courthouses across the country without explaining why they would be carried out.
An e-mail sent to the Magdeburg court just said an explosive device hidden in the courthouse would be detonated on Jan 11.
Police across the country searched the premises of courts for explosive devices with the help of sniffer dogs. In Wiesbaden, they blocked roads after a suspicious package was found at the courthouse.
Cybercrime experts are trying to find the source of the threatening emails.
Brandenburg police evacuated some 200 people from the courthouse at Jagerallee in Potsdam before launching the search for explosive devices.
A police officer told Berliner Morgenpost that they received the bomb threat at 7.45 am and took all steps for the safety of the public.
Traffic movement in Jagerallee was not affected by the search operation.
Although no explosive devices were found in any of the courthouses during the searches, German police did not treat the threatening emails as a hoax. None of the courthouses were opened to public again after the extensive search operations.
In the past weeks, district courts in Schleswig-Holstein has received similar threats which proved to be false alarms. Germany is on high alert after lone wolf attacks in Europe.