"There was a tip from Lebanon - a warning tip," said Stefanie Amft, a spokeswoman for German federal police. She gave no further details, except to say it was part of a global threat. "It is known that Germany is part of this worldwide threat," she said.
Germany was alerted after Lebanese authorities arrested a suspect on Thursday who was believed to have phoned a threat to the German Embassy in Beirut earlier in the week, a senior Beirut police official said.
The official, speaking on condition of anonymity because of the sensitivity of the investigation, said suspect Mohammed Naddoum was arrested after allegedly threatening to strike German security targets.
"Using special technology, the police were able to trace the man's location and identity and arrest him," the official said.
Naddoum confessed to making the call and having ties to al-Qaeda, the official said, adding that "Investigations are still under way to confirm his affiliations and intentions."
Report: Explosives already inside Germany
The official said police also arrested a Palestinian identified as Khodr al-Hinnawi on Friday after Naddoum repeatedly mentioned his name in interrogations. Police were in contact with officials from the German Embassy in Lebanon, the official said.
Germany's Focus magazine identified the suspect as "Mohammed N." and reported that he was a Syrian accused of al-Qaeda ties. It did not cite its sources. The suspect allegedly said a German-Turk, a Saudi and an Australian already were in Germany planning an attack on Berlin's Justice Ministry or other agencies to avenge the
prosecution of al-Qaeda suspects in that country, the Focus report said. It said explosives for the alleged attack were already inside Germany.
A Justice Ministry spokeswoman, speaking on customary condition of anonymity, refused to confirm any details but said officials were aware of the issue and had taken
"increased security measures" to protect employees.