German police arrested a third suspect Friday in connection with a failed attempt to blow up two trains, federal prosecutors said.

The man, whose identity was not released, was picked up in the southern city of Konstanz on suspicion of membership in a terrorist organization, attempting to set off an explosion and multiple counts of attempted murder. Prosecutors said he was an associate of Youssef Mohamad el Hajdib, one of two Lebanese men accused of planting the bombs July 31.