A Norwegian court on Monday identified the suspect in a deadly rampage at a gay bar in Oslo as Zaniar Matapour, a Norwegian citizen of Iranian origin, as police advised organizers of a demonstration of solidarity in honor of its victims to cancel the event.
Police had originally given approval for Monday's planned gathering outside Oslo Town Hall by the city's LGBTQ community.
But they later advised organizers to cancel as the scope of the event had grown and due to security concerns, with Norway having raised its terrorism threat assessment to its highest level following Saturday's attack.
Oslo Pride, one of the backers of Monday's demonstration and the organizer of the annual Pride celebrations that had been due to take place on Saturday, was not immediately available for comment.
Police described him as a radicalized Islamist with a history of mental illness.
The court will decide on the initial terms of Matapour's detention during the investigation into the mass shooting. He will undergo a psychiatric evaluation as part of that on Monday, police said.
He was apprehended by passers-by who chased him down the street. Police arrived at the scene five minutes after receiving the first emergency calls and took him into custody.
Known to security forces
Intelligence services said they had been aware of Matapour since 2015 and that he had been part of a network of Islamist extremists in Norway.
"Around 2015 we were worried about this person," Roger Berg, acting head of Norway's police intelligence service, PST, told private broadcaster TV2 on Saturday.
"We have followed him, to a degree. In more recent times, he was not one of the people we were the most worried about."
"We have followed him, to a degree. In more recent times, he was not one of the people we were the most worried about."
Roger Berg, acting head of Norway's police intelligence service
The suspect's lawyer, John Christian Elden, did not reply to a Reuters request for comment.
He told TV2 it was not possible to draw any conclusions about the motives or reasons for the attack. "It is far too early to do so," he said.
Matapour is accused of murder, attempted murder and terrorism. His response to the accusations is not known.
He moved to Norway as a child with his parents, became a father and for several years lived mainly off benefits, tabloid VG reported.