Authorities in the northern German city of Hamburg announced on Saturday that a Palestinian asylum-seeker went on a terrorist spree in a supermarket, resulting in the murder of a man and injuries to six people.Hamburg’s interior minister said security officials had been aware that the 26-year-old Ahmad A. was an Islamist. Eyewitnesses at the supermarket reported Ahmad shouted “Allahu akbar” during the attack.“Suddenly I saw a man smeared with blood running along the other side of the road with a knife,” eyewitness Ralf W. told the mass-circulation Bild daily. Ralf said Ahmed yelled “Allahu akbar” as he fled the supermarket.A second eyewitness told the NTV that “as he was running out... he held up his arms and shouted ‘Allahu akbar.’”“We have no clear information as to the motive or the number of wounded,” Hamburg police said in a tweet. “It was definitely a lone attacker.” They said initial reports about a possible robbery had not been substantiated.Olaf Scholz, the mayor of Hamburg, said the Ahmad could not be deported because he did not have personal identity papers. The mayor said Ahmed was egged on by “hate.”Scholz added, “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.” Police said passersby tackled the man after he fled the scene, injuring him slightly, before plainclothes police officers could take him into custody.The German news wire service DPA reported that the authorities launched an investigation into connections between Ahmad and the radical Salafist movement.German media reported that Ahmad was born in the United Arab Emirates.Conflicting reports said Ahmad either used a machete or kitchen knife to stab to death a 50-year-old man who is believed to be a German citizen.Police said that Ahmad “struck out wildly.” He wounded a 50-year-old woman and four men.Another 35-year-old man was hurt while overpowering the attacker in the street alongside other passersby shortly after the killing.Police have been on high alert in Germany since a spate of attacks on civilians last year, including a December attack on a Berlin Christmas market, when a hijacked truck plowed into the crowds, killing 12 and injuring many more.Security has been a campaign issue ahead of the September 24 parliamentary elections, in which Chancellor Angela Merkel is expected to win a fourth term in office. Newspaper Bild showed a picture of the alleged Hamburg attacker sitting in the back of a police car, his face concealed with a bloodied shroud.A video on its website showed a helicopter landed outside the supermarket with armed police in body armor patrolling the neighborhood.Reuters contributed to this report.