The suspect in Norway's twin attacks that killed at least 92 people admitted responsibility and said the carnage was long planned as the nation mourned victims of its worst violence since World War II.
Anders Behring Breivik, 32, was arrested for allegedly shooting at least 85 people dead at a youth Labour Party meeting on an island and killing seven more in a car bomb explosion which ripped through government buildings in Oslo.
"He admitted responsibility," Behring Breivik's lawyer Geir Lippestad told Norwegian media. While there was no official confirmation of the man's identity, he was widely named as Anders Behring Breivik by local media.
"He feels that it was cruel to have to carry out these acts but that, in his head, it was necessary," Lippestad said.
Oslo police spokeswoman Viola Bjelland said on Sunday that the suspect was "cooperative."
King Harald V, Prime Minister Jens Stoltenberg and other ministers were to attend mass at Oslo cathedral on Sunday morning.
A rambling 1,500-page tract apparently written by Behring Breivik said he has been preparing the "martyrdom operation" since at least autumn 2009.
The Internet document -- part diary, part bomb-making manual and part political rant in which he details his Islamophobia -- explains how he set up front mining and farming businesses to prepare the attacks for which he was arrested on Friday.
"The reasoning for this decision is to create a credible cover in case I am arrested in regards to the purchase and smuggling of explosives or components to explosives -- fertiliser," the tract says.
As harrowing testimony emerged from the summer camp where scores of youngsters were mown down, Norway was struggling to understand how a country famed as a beacon of peace could experience such bloodshed on its soil.
"Never since the Second World War has our country been hit by a crime on this scale," premier Stoltenberg told journalists as police searched for more bodies on the idyllic Utoeya island near Oslo.
"Many of those who have died were friends. I know their parents and it happened at a place where I spent a long time as a young person... It was a paradise of my youth that has now been turned into hell."
The toll could rise further as the search continued for four or five people still missing from the island, aided by a mini-submarine and Red Cross scuba divers.
Blond-haired Behring Breivik described himself on his Facebook page as "conservative", "Christian", and interested in hunting and computer games like World of Warcraft and Modern Warfare 2, reports said.
He also described himself as director of Breivik Geofarm, an organic farm that may have given him access to chemicals used in the production of explosives.
Police spokesman Roger Andersen described the suspect as a "Christian fundamentalist", adding that his political opinions leaned "to the right".
The head of the populist right-wing Progress Party (FrP) confirmed Behring Breivik had been a party member between 1999 and 2006 and for several years a leader in its youth movement.
He stopped paying his subscription before ending his membership, according to the party.
Anti-fascist monitors meanwhile said Behring Breivik was also a member of a Swedish neo-Nazi Internet forum named Nordisk, which hosts discussions on topics ranging from white power music to political strategies for crushing democracy.
The attacks on Friday afternoon were western Europe's deadliest since the 2004 Madrid bombings, carried out by al-Qaeda.
Friday's attacks began with a car bomb which seared through landmark buildings including Stoltenberg's office and the finance ministry. It is thought that the car-bomber then caught a ferry to nearby Utoeya island wearing a police sweater.
On arrival, he claimed to be investigating the bomb attack and began opening fire with an automatic weapon. The shooting spree lasted for an hour and a half.
Witnesses described scenes of horror among the more than 500 people attending the youth camp. Some who tried to swim to safety were even shot in the water.