German investigators said Thursday they suspected a "xenophobic motive" behind shootings at a shisha bar and a cafe that left 10 dead overnight in the city of Hanau.
Hours after police found the suspected gunman dead at his home in the early hours of Thursday following a huge manhunt, federal counter-terror prosecutors took over the case.
The probe was of "particular importance" and there were "signs of a xenophobic motive", a spokesman for the prosecutors told AFP.
Sources close to the investigation confirmed media reports that text and video material was found at the home of the perpetrator, who media reported was a 43-year-old man identified only as Tobias R.
King's College London counter-terrorism expert Peter Neumann tweeted of the text that it contained "various, but mostly extreme right views, with a do-it-yourself ideology cobbled together out of parts found on the internet".
"The pattern is clear, and not at all new," he added.
Meanwhile media including public broadcaster ARD reported that a second body discovered at the property belonged to the man's mother.
- A dozen shots -
The attacks occurred at two bars in Hanau, about 20 kilometres (12 miles) from Frankfurt, where armed police quickly fanned out and police helicopters roamed the sky in the search for those responsible for the bloodshed.
The first attack occurred at a bar in the Heumarkt district in central Hanau around 10 pm (2100 GMT), reports said.
A gunman reportedly rang the doorbell and shot at people in the smoking section, killing five including a woman, mass-market daily Bild said.
"The victims are people we have known for years," the bar manager's son told German news agency DPA. Two employees were among the victims, according to the man, who was not at the bar during the shooting. "It is a shock for everyone."
Police said one of those injured in the attack had also died.
The attacker, or attackers, fled the scene by car, according to police. There was then a second shooting at the Arena Bar.
Three people were killed outside the building, local media said, with witnesses reporting hearing a dozen shots.
A silver Mercedes-Benz covered by what looked like a survival blanket could be seen behind a police cordon and surrounded by officers outside the Arena Bar, with shattered glass on the ground.
- 'Horror scenario' -
The mayor of Hanau, Claus Kaminsky, told Bild that it had been "a terrible night".
"You could not imagine a worse night. It will of course keep us busy for a long, long time and remain a sad memory.
"I am deeply moved," he said. "Just the fact that eight people have lost their lives has shaken me up. But I ask all citizens not to speculate.
"The police must have the chance to clear up the situation and investigate -- until then, we should wait with prudence, no matter how hard this may be."
Katja Leikert, the MP for the region, said it was "a real horror scenario".
"On this dreadful night for Hanau, I would like to express my deepest condolences to the relatives of those killed. I hope the injured will recover quickly," she said.
Germany has been targeted in recent years by several extremist attacks, one of which killed 12 people in the heart of Berlin in December 2016.
Far-right attacks have become a particular concern for German authorities.
In October, a deadly anti-Semitic gun attack in the eastern city of Halle on the holy day of Yom Kippur underscored the rising threat of neo-Nazi violence. The rampage, in which two people were shot dead, was streamed live.
Last June, conservative politician Walter Luebcke, an advocate of a liberal refugee policy, was shot at his home.
On Friday police arrested 12 members of a German extreme right group believed to have been plotting "shocking" large-scale attacks on mosques similar to the ones carried out in New Zealand last year.
German-Turkish Islamic organisation Ditib, which funds around 900 mosques in Germany, called for greater protections for Muslims in the country, saying they "no longer feel safe" in Germany.