A still image from an undated video Islamic State posted July 19, 2016 in which a man whom it identifies as the Afghan refugee who attacked passengers with an axe on a train in Germany vows to carry out a suicide mission and urges other Muslims to do the same. Social Media via REUTERS TV

A still image from an undated video Islamic State posted July 19, 2016 in which a man whom it identifies as the Afghan refugee who attacked passengers with an axe on a train in Germany vows to carry out a suicide mission and urges other Muslims to do the same. Social Media via REUTERS TV

A still image from an undated video Islamic State posted July 19, 2016 in which a man whom it identifies as the Afghan refugee who attacked passengers with an axe on a train in Germany vows to carry out a suicide mission and urges other Muslims to do the same. Social Media via REUTERS TV

July 20, 2016 5:27 AM (UTC+8)