German investigators said on Tuesday that they suspect an Islamic extremist motive behind a deadly knife attack by a Somali man this past Friday.
Authorities in the state of Bavaria said evidence was mounting that the suspect, a Somali asylum seeker with a history of mental problems and only temporary permission to remain in Germany, may have been radicalized, AFP reported.
"The Bavarian Central Office for Extremism and Terrorism has taken over the probe because an Islamist motive is likely," Bavarian state prosecutors and the state criminal investigations office said in a statement quoted by the news agency.
The 24-year-old man on Friday went on a knife rampage in the city of Wurzburg, stabbing three women to death and leaving six other people seriously injured.
The Somali suspect, who arrived in Germany in 2015, struck in the city center, first at a household goods store before moving on to a bank. He was cornered by bystanders, then overpowered by police after they shot him in the thigh.
Investigators found records showing that he had been treated at a psychiatric institution, and police said he was not a known Islamist.
Bavarian authorities said a number of factors made an Islamic extremist motive appear probable, including witness accounts that the suspect cried "Allahu Akbar" during his killing spree and spoke of "jihad" from his hospital bed after he was taken into custody.
Germany has been hit by several terrorist attacks in recent years.
In one attack, a 17-year-old Afghani with an axe attacked passengers on a train in Wurzburg before being shot dead by security forces.
In a second incident, an attacker set off a bomb in a restaurant in Ansbach, killing himself and wounding 12 others.
The worst such attack took place in December of 2016, when Tunisian terrorist Anis Amri killed 12 people and injured dozens more when he drove a truck into a Christmas market in Berlin.
In early October, a knife-wielding attacker killed one tourist and seriously injured another in the city of Dresden. Prosecutors later said the incident is being treated as a terrorist attack.