Authorities are investigating the stabbings of nine people at a Minnesota shopping centre as a potential act of terrorism.
Such a finding would realise long-held fears of a terror attack in the immigrant-rich state, which has struggled to stop the recruiting of its young men by militant groups including Islamic State.
A young Somali man dressed as a private security guard entered the Crossroads Centre in St Cloud over the weekend wielding what appeared to be a kitchen knife.
The city’s police chief said the man reportedly made at least one reference to Allah and asked a victim if he or she was Muslim before attacking.
The rampage ended when the man was shot dead by an off-duty police officer. None of the injured suffered life-threatening wounds.
The motive of Saturday’s attack is still unclear, but FBI special agent-in-charge Rick Thornton said on Sunday the incident was being investigated as a “potential act of terrorism” and that Islamic State had claimed responsibility.
It was not clear whether the attacker was radicalised.
Authorities were digging into his background and possible motives, looking at social media accounts and electronic devices and talking to his associates, Mr Thornton said.
The attack in St Cloud, a city of about 65,000 people, began shortly after an explosion in a crowded New York City neighbourhood injured 29 people.
Hours before that, a pipe bomb exploded in Seaside Park, New Jersey, before thousands of runners were due to participate in a charity race.
There was no immediate indication the incidents were linked.
Minnesota governor Mark Dayton planned to meet with St Cloud’s mayor and other local officials on Monday to discuss the case.
It does not appear anyone else was involved in the attack, which began at about 8pm local time and was over within minutes, police chief Blair Anderson said.
Attack condemned
Leaders of the Somali community in central Minnesota united on Sunday to condemn the stabbings.
They said the suspect - identified by his father as 22-year-old Dahir A Adan - does not represent them, and they expressed fear of backlash.
Minnesota has the nation’s largest Somali community, with census numbers placing the population at about 40,000, though community activists say it is higher.
Terror recruiters have targeted young Somalis in recent years.
More than 20 young men have left the state since 2007 to join al-Shabab in Somalia, which the US considers a terrorist group.
Roughly a dozen people have left in recent years to join militants in Syria.
In addition, nine Minnesota men face sentencing on terror charges for plotting to join the Islamic State group.
The possibility of an attack on US soil has been a major concern for law enforcement.
Stopping terror recruiting has been a high priority, with law enforcement investing in community outreach and the state participating in a federal project designed to combat radical messages.
If Saturday’s stabbings are ultimately deemed a terrorist act, it would be the first carried out by a Somali on US soil, said Karen Greenburg, director of the Centre on National Security at Fordham University School of Law.
St Cloud mayor David Kleis said an attack like Saturday’s is the type of concern that keeps him “up at night”.
An Islamic State-run news agency, Rasd, claimed on Sunday that the attacker was a “soldier of the Islamic State” who had heeded the group’s calls for attacks in countries that are part of a US-led coalition against the group.
It was not immediately clear if the extremist group had planned the attack or even knew about it beforehand.
Islamic State has encouraged so-called “lone-wolf” attacks, and has also claimed past attacks that are not believed to have been planned by its central leadership.
Authorities have not identified the attacker, but his father, Ahmed Adan, told the Minneapolis Star Tribune his son's name through an interpreter.
Ahmed Adan said his son was born in Kenya but was Somali and had lived in the US for 15 years. Local activists also identified Dahir Adan as Somali.
Ahmed Adan said police told him at about 9pm on Saturday that his son had died at the shopping centre and that the family’s apartment had been searched, with photos and other materials seized.
He said police said nothing to him about the attack and that he had “no suspicion” that his son had been involved in terrorist activity, the newspaper reported.
It was not clear what type of security uniform the attacker was wearing or whether he may have previously worked at the shopping centre.
Authorities said on Sunday he was not a current employee at the shopping centre.
Police had had three previous encounters with the attacker, mostly for minor traffic violations, Mr Anderson said.
A spokesman for St Cloud State University confirmed that Adan was a student there, but that he had not been enrolled since the spring semester.
Victims
Mr Anderson said the man began attacking people right after entering the shopping centre, stabbing people in several spots.
The victims included seven men, one woman and a 15-year-old girl.
Five minutes after authorities received the first 911 call, Jason Falconer, a part-time officer in the city of Avon, began shooting the attacker as he was lunging at him with the knife, Mr Anderson said, and continued to engage him as the attacker got up three times.
“He clearly prevented additional injuries and potential loss of life,” Mr Anderson said.
“Officer Falconer was there at the right time and the right place.”
Photos and video taken hours after the incident showed groups of shoppers waiting to be released from the shopping centre.
Sydney Weires (18) and two of her friends were shopping when the stabbings happened.
Ms Weires said she saw a man who appeared to be a security guard sprinting down the hallway, before two men stumbled out.
“One was covered in blood down his face,” she said, and the other man had blood on his back.
“They were screaming, ‘Get out of the mall. Someone has a knife’,” Ms Weires said.
Mr Falconer was shopping when he confronted the attacker.
He told a newspaper he was not hurt and declined to talk further, citing the ongoing investigation.
PA