A hand-painted flag of so-called Islamic State has been found in the room of an Afghan refugee accused of carrying out an axe and knife attack on a southern German train, officials say.
The 17-year-old injured four people from Hong Kong, two critically, in the attack in Wuerzburg on Monday evening. He was shot dead by police as he fled.
He had shouted Allahu akbar” (“God is great”), a witness said.
The attack comes days after a deadly IS-claimed attack in Nice in France.
Joachim Herrmann, the interior minister of the state of Bavaria, told German TV the flag had been found among the teenager’s belongings in his room in his foster home in the nearby town of Ochsenfurt.
Mr Herrmann said it was too early to say whether the teenager was a member of an Islamist group or had become self-radicalised in recent times.
Two of those injured are in a critical condition.
Another woman was injured outside the train as the man fled. Fourteen people were treated for shock.
The teenager, who had claimed asylum after travelling to Germany as an unaccompanied minor, had been living with the foster family since moving from a refugee centre in the town. Investigators are talking to the foster family.
Last year Germany registered more than one million migrants, including more than 150,000 Afghans, although the number has slowed dramatically this year since new EU measures were taken to stop the flow.
The South China Morning Post said it was believed four of the people injured were a 62-year-old man, his 58-year-old wife, their daughter, 27, and her boyfriend, 31, from Hong Kong. The 17-year-old son travelling with them was not hurt, it said.
A source told the paper the father and boyfriend had tried to protect the other members of the group.
Hong Kong Chief Executive Leung Chun-ying has condemned the attack and expressed his sympathy to the victims. Immigration officials from the city will accompany family members to Germany.
The attack happened at about 21:15 (19:15 GMT) on the train which runs between Treuchlingen and Wuerzburg.
Police said the attacker had fled the train but was chased by officers who shot him dead.
One local man told DPA news agency that the train carriage where the attack took place “looked like a slaughterhouse”.
The BBC’s Damien McGuinness in Berlin says there is nervousness in Germany about attacks by Islamist extremists following the attacks across the border in France.
Islamic State said one of its followers had carried out the lorry attack in Nice that killed 84 people on Bastille Day.
In May, a man reportedly shouting “Allahu akbar” killed a man and wounded three others in a knife attack at a railway station near the German city of Munich.
He was later sent to a psychiatric hospital and authorities said they had found no links to Islamic extremism.
Source: BBC News