New Zealand police shot and killed a known Islamic State sympathizer who stabbed six shoppers with a knife at a supermarket in Auckland on Friday, with Prime Minister Jacinda Ardern describing what happened as "terrorist attack."

The attack, which left several multiple seriously injured, occurred at around 2:40 p.m. at the Countdown supermarket in the suburb of New Lynn, Ardern told a press conference.

Police respond to a mass stabbing incident at a supermarket in Auckland, New Zealand on Sept. 3, 2021. (Getty/Kyodo) 

"What happened today was despicable. It was hateful, it was wrong," Ardern said, while stressing it "was carried out by an individual, not a faith, not a culture, not an ethnicity."

The assailant was identified as a Sri Lankan national who arrived in New Zealand in 2011 and had been identified as a threat by the nation's security agencies since 2016.

Police had followed the man from his home to the supermarket as part of constant monitoring and shot and killed him within 60 seconds of the attack beginning, Ardern said.

According to a report by the New Zealand Herald, police had previously arrested him for allegedly planning a "lone wolf" knife attack.

When reporters asked Ardern why the man had been allowed to be in the community, she stressed that "agencies were using every single possible means available to them to protect the New Zealand public from this individual," but his past actions had not reached a threshold that allowed authorities to put him behind bars.

Multiple inquiries into Friday's attack will be undertaken, including those by the coroner and the Independent Police Conduct Authority of New Zealand, Ardern said.

Prime Minister Jacinda Ardern speaks to the media at a press conference with the details of an Auckland supermarket stabbing incident on Sept. 3, 2021, in Wellington, New Zealand. (Getty/Kyodo)

The six people injured in the attack have been taken to hospitals across Auckland, with three in a critical condition, one in a serious and two in a moderate condition, St John New Zealand ambulance service said in a statement.

Witnesses described scenes of mass panic caused by the attack to the online news portal Stuff.

"People were panicking, and it was a gridlock trying to get out of New Lynn," said Brittany Denyer who was about to enter the supermarket when police officers ran up to her and told her to "hurry up and evacuate immediately," the Stuff report said.

Michelle Miller said she was doing her afternoon shop in the supermarket when she saw the nightmarish scenes unfold, according to the report.

The offender was "running around like a lunatic," Miller was cited as saying. "He was attacking people. All I heard was a lot of screaming."

New Zealand has been on heightened alert for terrorist attacks since March 2019, when a white supremacist gunman killed 51 people at two mosques in the city of Christchurch.

Four people were stabbed at another Countdown supermarket in the South Island city of Dunedin in May, but police at the time said it was unlikely the attack was an act of terrorism.