Oslo terror attacks: Suspected gunman in custody
The suspect arrested on Utoeya island near Oslo after a gun attack on a youth camp, was wearing police clothes, spokesman for Oslo police Anders Frydenberg said.
The man, now in police custody, has never been a member of the police force, he added.
Norway has been hit by twin attacks - a massive bomb blast in the capital and a shooting attack on young people at a governing Labour Party youth camp.
At least 80 people are reported to have died at the youth camp and 16 in the bomb attack.