German police say a man of Tunisian immigrant background has stabbed a security worker in the head at Duesseldorf airport. The employee had to undergo surgery but is not in a life-threatening condition. The dpa news agency reported that the 24-year-old suspect approached the security employee from behind on Tuesday morning before stabbing him with a knife. The suspect then ran away, but was apprehended shortly afterward. Police did not reveal his identity, but said it appears he has psychological problems and did not have any political motivation.