BERLIN (Reuters):

German politicians warned at the weekend of a growing terrorism threat and called for new measures to counter it after authorities said a plot to blow up trains had failed only because the crude bombs did not go off.

Police said on Friday two men, who may have been part of a wider Islamic militant network, had come close to exploding makeshift bombs on two trains in Dortmund and Koblenz in July.

"The situation is very serious," Interior Minister Wolfgang Schaeuble said in an interview with German public television. "The danger has never been as high."

German police on Saturday detained one of two men they suspect of planting the bombs. The two were caught on video cameras in Cologne train station, dragging suitcases which contained the explosive devices on to the trains.

The federal prosecutor has described the man as a 21-year-old Lebanese student named Youssef Mohamad E.H., who has been living in Germany for two years. Police seized him in the northern city of Kiel.

Although the bombs, made with propane tanks and crude detonating devices, failed to go off, authorities said the complexity of the plot suggested the men had not acted alone.

The second suspect is still at large and the focus of an intense manhunt.