At least 100,000 people rallied in Oslo and tens of thousands more marched in cities across Norway on Monday in a nationwide expression of grief and unity over the massacre of 76 people by Anders Behring Breivik.
Mr. Breivik told a judge in a closed hearing on Monday his bombing and shooting rampage aimed to save Europe from a Muslim takeover, and said that "two more cells" existed in his group.
Police said they could not rule out the possibility that others were involved in Friday's attacks and they revised down the death toll to 76 from 93: eight dead in a bomb blast in Oslo and 68 at a Labour Party youth camp on Utoeya island.
Norwegian Prime Minister Jens Stoltenberg addressed the evening crowd, many of them holding up red and white roses for remembrance, his voice trembling with emotion: "By taking part you are saying a resounding 'yes' to democracy."
He called the Rose March a "march for democracy, a march for tolerance, a march for unity".
"Evil can kill a person but never conquer a people," he said.
In a country of 4.8 million, where a single murder makes front-page news, the solidarity rally was probably the biggest since World War Two.
"We are a small society and I think that makes everyone feel affected whether directly involved or not," said Jonas Waerstad, 26, who was one of the marchers.
Earlier in the day, a handful of enraged protesters awaited Mr. Breivik at Oslo District Court.
"Get out, get out!" shouted one, banging on a police car he wrongly believed contained the self-confessed mass killer. In fact police drove Mr. Breivik to the court in another vehicle.
"Everyone here wants him dead," he said, adding that he knew one of the dead and three survivors of the attacks.
"We want to see him really hurt for what he did," said Zezo Hasab, 32, among the jeering protesters outside the court.
Mr. Breivik had wanted to explain in public why he perpetrated modern-day Norway's worst peacetime massacre. He was denied a public platform, but judge Kim Heger in his news conference, gave an account of what the accused 32-year-old had said.
After the hearing, a police jeep drove away carrying an unshaven Mr. Breivik, with close-cropped blond hair and wearing a red jumper with a lighter red shirt underneath.
Police handling of the crisis may come under more scrutiny after the revision to the death toll, which a police spokesman attributed to difficulties in gathering information at Utoeya.
The Norwegian daily Dagsavisen asked "Why didn't you come earlier?" citing screams by youths as police arrived on the island – an hour after they were notified of the shooting.
Police efforts to reach the island stalled after one boat, overloaded with officers and equipment, was forced to stop when it began to take on water.
Mr. Breivik's name had appeared, via Interpol, on a list of 50-60 Norwegians after he paid 120 Norwegian crowns ($22.16) to a Polish company that was under surveillance because of its sale of chemicals, Norway's NRK television said.
Mr. Breivik leased a farm and bought fertilizers.
"We get masses of information about very many people," PST security police chief Janne Kristiansen told NRK. She said PST checked names on the list against PST watch lists but that "we had absolutely nothing on Behring Breivik" and it was dropped.
She said his Internet and Facebook profiles looked moderate although he took part in some extremist chat rooms.
It was not clear whether Mr. Breivik is in fact part of an organization, although he has written about a revival of the Knights Templar, a medieval order of crusading monks.
Judge Heger said Mr. Breivik had accused the ruling Labour Party of betraying Norway with "mass imports of Muslims".
He said his bombing of government buildings in Oslo and massacre at a summer camp for Labour's youth wing was aimed at deterring future recruitment to the party.
"The goal of the attack was to give a strong signal to the people," the judge quoted Mr. Breivik as saying.
Mr. Breivik's custody can be extended before a trial on terrorism charges. Police say the trial could be a year away. Judge Heger said he had ordered Mr. Breivik detained in solitary confinement for eight weeks, with no letters, newspapers or visits, except from a lawyer.
The detention, in line with a request from prosecutors, will allow them to investigate the case against Mr. Breivik.
In a rambling 1,500-page tract posted online just before the massacre, Mr. Breivik explained how violence was needed to rescue Europe from Islam, immigration and multiculturalism.
If he survived his assault and was arrested, this would "mark the initiation of the propaganda phase," he wrote.
The judge's decision to close the hearing to the public followed an outcry from Norwegians incensed at the possibility that Mr. Breivik would be allowed a public platform for his views.
A Facebook group called "Boycott Anders Behring Breivik" carried the message: "He has planned this stage, to get propaganda. Do NOT let him get that freedom ... Boycott all media describing the Norwegian terrorist and his beliefs."
The maximum jail term in Norway is 21 years, though that can be extended indefinitely if there is a risk of repeat offences.
The attack was likely to tone down the immigration debate ahead of September local elections, analysts said, as parties try to distance themselves from Mr. Breivik's beliefs and reinforce Norwegians' self-image as an open, peaceful people.
Party leaders have agreed to delay the start of campaigning for the polls until mid-August, Norwegian news agency NTB said.
Norway's immigrant numbers nearly tripled between 1995 and 2010 to almost half a million. Arguments that many were drawn by generous welfare handouts spurred the growth of the Progress Party which became Norway's second biggest in parliament after the 2009 election on a largely anti-immigration platform.
Mr. Breivik once belonged to the party, but left saying it was too politically correct. He then began scheming to "resist", burying ammunition, weight-lifting, storing credit cards and researching bomb-making while playing online war games.
After three months of making explosives on a remote farm, Mr. Breivik drove a hire car packed with the device to Oslo, detonating it outside government offices. He then drove to Utoeya, 45 km away.