At the end of 2003, El-Masri travelled from his home in Ulm to go on a short vacation in Skopje. He was detained by Macedonian border officials on 31 December 2003, because his name was identical (except for variations in Roman transliteration) to that of Khalid al-Masri, who was being sought as an alleged mentor to the al-Qaeda Hamburg cell, and because of suspicion that El-Masri's German passport was a forgery. He was held in a motel in Macedonia for over three weeks and questioned about his activities, his associates, and the mosque he attended in Ulm.