Federal prosecutors have taken over the investigation into a knife-and-axe attack on a German commuter train, suspecting the perpetrator of committing a targeted act "as a member of the so-called Islamic State" and raising the possibility of accomplices.
The Karlsruhe-based prosecutors took over the investigation from local prosecutors in the state of Bavaria, where the attack took place, amid mounting evidence of the 17-year-old's Islamist ideology.
In a statement announcing the move, the prosecutors also said they were probing whether there were "unknown accomplices or instigators" in the attack, which resulted in the perpetrator being shot dead.
The announcement seemed to contradict earlier statements by Interior Minister Thomas de Maiziere, who said the teenaged refugee - who injured five people during a rampage near the city of Wuerzburg late Monday - was a lone wolf "goaded" by Islamic State propaganda.
De Maiziere confirmed the authenticity of a video circulated by Islamic State supporters showing the adolescent waving a knife and vowing to commit an attack in Germany, but said there was no evidence he received direct instructions from the extremist group.
"It is perhaps a case that occupies a grey area between a crazed rampage and a terrorist act," de Maiziere said at a press conference held two days after the attack.
German media reported Wednesday that the perpetrator, registered in Bavaria as an Afghan asylum seeker, was in fact from Pakistan and may have faked his identity in order to improve his chances of gaining a residence permit.
Documents found in the adolescent's room showed that he had Pakistani citizenship, German public broadcaster ZDF reported citing security sources.
A hand-painted Islamic State flag and Pashto-language writings - including a goodbye note to his father and a text calling on Muslims to arm themselves - were also found in his room with a German foster family. Pashto is spoken in both Afghanistan and Pakistan.
De Maiziere said that the influx of underage refugees from conflict zones was dangerous because young people are more prone to traumatization and because their arrival creates a "vacuum" that will lead to a large inflow of family members.
Germany welcomed 1.1 million migrants in 2015, mostly from conflict zones including Syria, Afghanistan and Iraq. Nearly 15,000 of them were children who travelled to Europe without legal guardians.
The minister said that efforts to reduce the influx - which included a crackdown on people smugglers and the closure of the Western Balkan route - had been proven right, because a smaller refugee population would allow greater control over those susceptible to radicalization.
He also spoke about counter-terrorism measures put in place by the German government in recent months, adding that 11 terrorist attacks - including 10 on German soil - had been thwarted by security forces.
Two of the five people injured in the attack - a 62-year-old man from Hong Kong and his daughter's boyfriend, 30 - are still in critical condition, according to the Wuerzburg hospital where they are being treated.
Their families arrived in Germany on Wednesday.