German police have arrested a Syrian man on suspicion he was planning to carry out an attack after discovering that he had obtained material which could be used to build weapons or bombs.

Authorities say the suspect was arrested Saturday as he tried to cross the border from Germany to Denmark.

Stuttgart prosecutors say the 20-year-old man, whose identity was not released, had been living in a refugee shelter in southwest Germany.

Prosecutors said in a statement Thursday that there were no indications of a concrete threat.