German prosecutors on Thursday ordered the release of a Syrian man accused of helping two Lebanese men in a failed plot to blow up two trains, citing lack of evidence. Fadi al-Saleh, 23, was detained in southern Germany on allegations he did Internet research in preparation for the failed July 31 bombings. Though prosecutors said their investigation continued, they said in a statement that there was not enough evidence — including through the questioning in Lebanon of prime suspect Jihad Hamad — to hold al-Saleh any longer. "Further investigation, in particular questioning of Jihad H. — a fellow suspect arrested in Lebanon — did not the strengthen the suspicions against him in such as to justify keeping him in pretrial confinement," prosecutors said in a statement.Hamad, 20, along with Youssef Mohammed el-Hajdib, 21, are accused of planting bombs on July 31 in two trains at a railway station in the German city of Cologne. The pair were seen in grainy surveillance camera footage pulling wheeled suitcases. The bombs were found later in the day on regional trains, and authorities said that the detonators went off but failed to ignite the devices. El-Hajdib was arrested last month in Germany while Hamad was picked up in Lebanon along with three other subjects. Al-Saleh was arrested in the German city of Konstanz. All six have been charged by Lebanese prosecutors with attempting to kill a large number of people in the failed train attacks.