German officials say they have found a hand-painted flag of the so-called Islamic State in the room of the 17-year-old Afghan refugee who attacked passengers on a train in Southern Germany.
The revelation came after security officials said they had contacted the family the refugee was staying with in a bid to find out if there was a motive for his action.
Bavaria’s Interior Minister, Joachim Herrmann, 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.
Hermann however said it was too early say if the attacker was a member of the Islamic State or had become radicalised recently.
The Islamic State on Tuesday however claimed responsibility for the attack claiming the 17-year-old was one of its soldiers.
In a statement on its news agency Amaq, the IS said: “The perpetrator of the stabbing attack in Germany was one of the fighters of the Islamic State and carried out the operation in answer to the calls to target the countries of the coalition fighting the Islamic State.”
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, the BBC reports.
The 17-year-old injured several passengers, three of them seriously, when he suddenly attacked them with an axe and a knife.
He was later shot and killed by police who chased after him when he fled the train at an emergency stop. Police said he had tried to attack an officer.
The incident happened at about 9pm local time on the train which runs between Treuchlingen and Wurzburg in Bavaria.
Unconfirmed reports from German media say the youth shouted ‘Allahu Akbar’ or “God is Great” during the attack.
Germany is on alert for Islamist extremists following the attacks across the border in France.