(AFP) – German authorities have cast doubt on whether a teenager who went on an axe rampage on a Bavarian train was really an Afghan refugee, saying Wednesday he might have been from Pakistan. The Islamic State group released a video on Tuesday purportedly featuring the 17-year-old, who was shot dead by police following the train attack in which he injured five people, two of them critically. However, sources close to the German security services now think he might have pretended to be Afghan on arrival in Germany in 2015 in order to have a better chance at securing asylum, television station ZDF reported. In the IS video the youth uses phrases of a dialect of Pashto spoken in Pakistan and not Afghanistan and experts have indicated that his accent is also clearly Pakistani, ZDF said. A Pakistani document was also found in his room. The name he used in the video, “Mohammed Riyadh”, does not match the name under which he registered in Germany, Riaz Kahn, the station added. German authorities said they had authenticated the video. On Tuesday, authorities said they had found a hand-painted IS flag and what they called a suicide letter among the attacker’s belongings.