Two people were killed when shots were fired in front of a club in the Norwegian capital Oslo, which is popular in the queer scene. According to official information, 21 other people were injured, ten of them seriously. Shortly after the incident, a person was arrested near the crime scene, the police tweeted early Saturday morning.

“The police are treating the case as an act of terrorism,” the authorities said on Saturday. A suspect was arrested after shots were fired in three locations around 1 a.m. The shots were fired in the center of Oslo, near the London Pub gay club, a jazz club and a food stand.

Police chief Christian Hatlo said at a press conference on Saturday that the suspected perpetrator is an Iranian-Norwegian who is known to the domestic secret service, which is also responsible for countering terrorism.

He was also known to the police for minor offenses such as carrying a knife and drug possession. Operations manager Tore Barstad had already said during the night that everything indicated that it was a lone perpetrator.

The 40th Pride Parade was to take place in Oslo on Saturday. The organizers canceled this on Saturday morning. All other events related to the parade had also been canceled as a precaution, they said on Facebook.

According to the police, the arrested person has not yet commented. The police searched his home, NRK reported. Firearms were used in the attack, two of which were seized, NRK quoted Barstad as saying.

A reporter who was an eyewitness said he saw a man with a bag approach the scene, took a gun and started shooting. There was a panic in the nightclub, the station quoted another eyewitness as saying.

The Aftenposten newspaper reported that civilians helped arrest the suspect. “He seemed very sure of what he was aiming at,” an eyewitness told the Verdens Gang newspaper about the perpetrator. Another witness told the newspaper that the man had fired an automatic weapon and that the crime scene looked “like a war zone”. Several people with head injuries were lying on the ground.

Just eight months ago, a killing spree shook the Scandinavian country. A 38-year-old Dane attacked passers-by with bows and arrows and knives in the southeastern Norwegian city of Kongsberg last October, killing five of them, including a 52-year-old German woman.

At trial he pleaded guilty to murder and attempted murder. According to experts, the 38-year-old has suffered from paranoid schizophrenia since 2007. A court on Friday ordered the assassin to be held in a psychiatric institution for life.

The worst violent crime to date in Norway’s post-war period occurred on July 22, 2011. Anders Behring Breivik, now 42 years old and now calling himself Fjotolf Hansen, detonated a car bomb in Oslo’s government district on July 22, 2011, killing eight people .

He then massacred the participants of the annual summer camp of the youth wing of the Social Democratic Labor Party on Utøya. 69 mostly young people were killed on the island. Breivik named right-wing extremist and Islamophobic motives for his actions.

In the summer of 2012 he was sentenced by the Oslo District Court to the maximum sentence at the time of 21 years in preventive detention with a minimum term of ten years. This time frame included 445 days in custody.