A Norwegian-Iranian man embarked on a shooting spree in a gay bar and the surrounding streets in Oslo on Saturday, killing two people and injuring more than 20. 

The rampage took place inside and outside the London Pub, a well-known gay bar and nightclub open since 1979, as well as at one other bar in the center of the Norwegian capital in the early hours of the day as the city's LGBTQ+ community was due to celebrate its annual Pride parade, which is now called off upon police recommendations.

The 42-year-old suspect, identified as Zanyar Matapour, was detained minutes after the attack, according to police who said they believed he acted alone. Two weapons, a pistol and a fully automatic rifle, were retrieved from the crime scene. 

"There is reason to think that this may be a hate crime. We are investigating whether the Pride was a target in itself or whether there are other motives," police said, adding that the man was “suspected of murder, attempted murder and terrorist acts.” “The attack was also being investigated as “a possible act of terrorism.”

Norwegian police, who are not normally armed, will now carry guns until further notice as a precaution, Commander Benedicte Bjoernland said. Norway's PST intelligence service said that it was investigating whether there could be further attacks. 

The Nordic nation of 5.4 million has lower crime rates than many Western countries, although it has experienced hate-motivated shootings, including when Neo-Nazi extremist Anders Behring Breivik killed 77 people in 2011.