The 21-year-old is suspected of murder and violation of anti-terrorism legislation, the NRK broadcasting company reported, APA reports quoting sputniknews.
An Oslo court on Monday ruled to hold Philip Manshaus, a suspect in a mosque shooting incident, in custody for four weeks, local media reported.
The suspect's attorney said her client chose to exercise the right not to be questioned and did not admit his guilt.
On the photos from the courtroom, published by the NRK, Manshaus' neck and face is marked by scratches and bruises.
The Norwegian police said on Saturday that a man opened fire at the al-Noor Islamic Centre in the municipality of Baerum near Oslo. One person was injured in the attack. Media reported that soon after the mosque attack police discovered the body of a young woman which they later said she was Manshaus' stepsister.
The shooter, detained by the police, has been charged with murder.
At least a dozen people were in the Al-Noor Centre when an attacker started firing. He was quickly overpowered by the people there, and only managed to wound a 75-year-old man.
The attack on the mosque occurred as Muslims across the world celebrated the second day of the annual Hajj pilgrimage to Mecca, Saudi Arabia.