Investigators seek motive after Somali man kills 3

Investigators were racing yesterday to pinpoint the motive of a man who went on a knife rampage in the German city of Wuerzburg, killing three people and leaving five seriously injured. 

The suspect, a 24-year-old Somali who arrived in Wuerzburg in 2015, staged the attack in the city centre on Friday evening, striking at a household goods store before advancing to a bank.

He was later overpowered by police after they shot him in the thigh, Bavaria's interior minister Joachim Herrmann said.

Investigators found records showing that the man had been treated at a psychiatric institution, and police said he was not a known Islamist.

"The police investigation will determine if this was an Islamist act or if it was due to the psychiatric state" of the man, said Herrmann.

But the case was immediately seized on by the far-right AfD, with the party's co-chair Joerg Meuthen noting that a witness had reportedly heard the suspect shouting "Allah Akbar" (God is greatest). 

Meuthen lamented the latest "Islamist knife murders in the middle of Germany," adding that it was a "tragedy for the victims, who have my sympathy and another manifestation of Merkel's failed migration policy".

The AfD has railed that Chancellor Angela Merkel's decision to allow in more than one million asylum-seekers -- many fleeing Iraq and Syria -- since 2015 has contributed to a heightened security risk.

President Frank-Walter Steinmeier voiced shock at the "extreme brutality" of the crime.  "He will be held to account by the rule of law for this inhumane act," the president said.

Video footage circulating online showed passers-by trying to stop the suspect using folded chairs. A crowd of people gave chase before a police car arrived on the scene, one video showed.

While the perpetrator's motive remains unclear, Germany has been on high alert after several Islamist extremist attacks.