Excerpt:
A young Afghan who attacked passengers on a train in Bavaria with an ax had entered Germany last summer with a wave of migrants, officials said on Tuesday, raising more questions about Chancellor Angela Merkel's open-door refugee policy.
The 17-year-old, who a witness said shouted "Allahu Akbar" (God is Great) during the attack, severely wounded four Hong Kong residents on the train late on Monday, then injured a local woman after fleeing, before police shot him dead.
The case is likely to deepen worries about so-called "lone wolf" attacks in Europe and could put political pressure on Merkel, who has welcomed hundreds of thousands of migrants to Germany over the past year.