ST. CLOUD, Minn. » A man in a private security uniform stabbed nine people at a Minnesota shopping mall, reportedly asking one victim if he or she was Muslim before an off-duty police officer shot and killed him in an attack the Islamic State group claimed as its own.

None of the nine people who were stabbed in Saturday night’s attack received life-threatening wounds, St. Cloud police Chief Blair Anderson said. He said it doesn’t appear that anyone else was involved in the attack at the Crossroads Center in St. Cloud, which began at around 8 p.m. and was over within minutes.

At a news conference Sunday, FBI Special Agent-in-Charge Rick Thornton said the attack was being investigated as a possible act of terrorism and that agents were still digging into the attacker’s background and possible motives. Authorities were looking at social media accounts and the attacker’s electronic devices and talking to his associates, Thornton said.

An Islamic State-run news agency, Rasd, claimed 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 U.S.-led anti-IS coalition.

It was not immediately clear if the extremist group had planned the attack or even knew about it beforehand. IS has encouraged so-called “lone wolf” attacks. It has also claimed past attacks that are not believed to have been planned by its central leadership.

Authorities didn’t identify the attacker, but the Star Tribune of Minneapolis said the man’s father identified him as Dahir A. Adan, 22. Speaking to the newspaper through an interpreter, Ahmed Adan, whose family is Somali, said his son was born in Africa and had lived in the U.S. for 15 years.

A spokesman for St. Cloud State University confirmed that Adan was a student there, but has not been enrolled since the spring semester. Spokesman Adam Hammer said Adan’s intended major was information systems, which is a computer-related field.

Ahmed Adan said police told him around 9 p.m. Saturday that his son had died at the mall, and that police had raided the family’s apartment, seizing photos and other materials. He said police said nothing to him about the mall attack, and that he had “no suspicion” that his son had been involved in terrorist activity, the newspaper reported.

Anderson said police had had three previous encounters with the attacker, mostly for minor traffic violations.

According to Anderson, the attacker, dressed in a security uniform and wielding what appeared to be a kitchen knife, began attacking people right after entering the mall, stabbing people in several spots inside the building, including corridors, businesses and common areas.

Five minutes after authorities received the first 911 call, Jason Falconer, a part-time officer in the city of Avon, shot and killed the attacker. Anderson said Falconer fired as the attacker was lunging at him with the knife, and continued to engage him as the attacker got up three times.

“He clearly prevented additional injuries and potential loss of life,” Anderson said. “Officer Falconer was there at the right time and the right place,” he said.

Anderson earlier said the man reportedly made at least one reference to Allah and asked a victim if he or she was Muslim before attacking them.

Leaders of the Somali community in central Minnesota united to condemn the stabbings. They said the suspect does not represent the larger Somali community, and they expressed fear about backlash over the attack.

Minnesota has the nation’s largest Somali community, with census numbers placing the population at about 40,000. But community activists say the population — most of it in the Minneapolis area — is much higher. The immigrant community has been a target for terror recruiters in recent years. More than 20 young men have left the state since 2007 to join al-Shabab in Somalia, and 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.

For years, law enforcement officials have worried that young Somalis who embrace radical messages might carry out violence in the U.S. While the motive in Saturday’s stabbings isn’t yet known, if it turns out to be a terrorist attack, it would be the first carried out by a Somali on U.S. soil, said Karen Greenburg, director of the Center on National Security at Fordham University School of Law.

The attack in St. Cloud, a city of about 65,000 people 60 miles (95 kilometers) northwest of Minneapolis, began shortly after an explosion in a crowded New York City neighborhood injured 29 people. A suspicious device was found a few blocks away and safely removed. Hours before that, a pipe bomb exploded in Seaside Park, New Jersey, shortly before thousands of runners were due to participate in a charity 5K race. There was no immediate indication that the incidents were linked.

The mall remained closed Sunday. Of the nine victims — seven men, a woman and a 15-year-old girl — three remained hospitalized, officials said.

Photos and video of the mall taken hours after the incident showed groups of shoppers waiting to be released, including some huddled together near a food court entrance.

Harley and Tama Exsted, of Isle, were in St. Cloud to watch their son play in a college golf tournament and were in the mall when the attack happened.

“All of a sudden I heard pop, pop, pop,” Harley Exsted told the St. Cloud Times. “I thought someone tipped over a shelf. All of a sudden these people started running. I just saw everybody running our way.”

The couple were unharmed and said they helped another woman who was running from the scene to her car.

Falconer, who was shopping when he confronted the attacker, is the former police chief in Albany, which is about 15 miles northwest of St. Cloud, and the president and owner of a firing range and firearms training facility, according to his LinkedIn profile. His profile says he focuses on firearms and permit-to-carry training, and also teaches “decision shooting” to law enforcement students at St. Cloud State University.

No one answered the door late Sunday at a home address listed for Falconer, and a voicemail box for a telephone listing was full and not accepting new messages. In a brief interview with the Star Tribune, Falconer said he had “been trying to stay away from it all, for the time being.”

He told the newspaper he wasn’t hurt and declined to talk further, citing the ongoing investigation for not saying more.