"I am outraged by the vicious attack that killed at least one Hamburger today," he said.

"It makes me especially angry that the perpetrator appears to be a person who claimed protection in Germany and then turned his hate against us."

Citing security sources, Berlin newspaper Der Tagesspiegel reported that the 26-year-old perpetrator was known to police as an Islamist. News agency DPA reported that security authorities were investigating evidence the man had Salafist ties.

The attacker stabbed to death a 50-year-old man believed to be a German citizen

Police said that he "struck out wildly" at others, wounding five more in the supermarket - a 50-year-old woman and four men aged 19, 56, 57 and 64.

Another 35-year-old man was hurt while overpowering the attacker in the street alongside other passers-by shortly after the killing.