BERLIN, Jan. 12 (Xinhua) -- German authorities have opened an investigation into the dangers of possible terror attacks in Germany, local media reported Saturday.

    German prosecutors have started to investigate into claims that terrorists planned to blow up a truckload of explosives in Germany, said a report released by Der Spiegel magazine two days before its publication.

    According to the report, German authorities received warnings from their Lebanese counterpart and have since stepped up security measures.

    The explosives, believed to be still on the way, are supposed to be coming in to the northern German port city of Rostock through Russia and Finland, said the report.

    The attackers were potentially acting in revenge for the arrest of Fritz Martin Gelowicz and other suspects who allegedly planned to attack a U.S. military base in Germany, it said. Gelowicz was arrested in Germany in September, 2007.

    The attackers may also be acting against the recent conviction of Jihad Hamad, who failed to bomb the commuter trains in the western German city of Kologne in July 2006. The devices failed to explode because of faulty detonators.

    Hamad, a 22-year-old Lebanese citizen, was sentenced by a Lebanese court last month to 12 years in prison.