German police have arrested three Syrian nationals in the northern state of Schleswig-Holstein suspected of being sent to Germany by the militant Islamic State group, prosecutors said on Tuesday. Prosecutors suspect the three men, aged between 17 and 26-years old, were dispatched to Germany in Nov. 2015 “either to carry out a mission that they had been informed about or to wait for further instructions”. It was unclear where any attack would have taken place. “Concrete missions or orders have not so far been found in the course of investigations carried out so far,” said federal prosecutors in a statement.Around a million migrants arrived in Germany last year and concerns about their presence here have increased after a recent series of violent attacks, three of which were carried out by asylum seekers. Of those, two were claimed by Islamic State.