Jittery Norwegians tried to restore some normality on Wednesday after mass killings by a far-right zealot traumatized the nation, but a security alert forced the evacuation of Oslo station, keeping nerves on edge.
Norway's domestic intelligence chief said she believed Anders Behring Breivik had acted alone in killing 76 people in a bomb attack and shooting spree, and contested an assertion by the killer's lawyer that his client was probably insane.
Oslo's central station was evacuated after a suspicious suitcase was found on a bus, and all train and bus services were halted. Police cars, fire trucks and ambulances ringed the station, but police said later the suitcase was harmless.
"Nothing was found that was of interest to the police," Chief Superintendent Tore Barstad told reporters, adding that the suitcase search had no known link with Friday's attacks.
In another false alarm, police retracted a search alert for a man who identified with Mr. Breivik, saying in fact they wanted to detain a disturbed man with no link to the killer.
A cabinet minister made a symbolic return to her office in Oslo's government district where Mr. Breivik detonated a powerful home-made bomb that killed eight people on Friday.
The bomb blew a hole in Prime Minister Jens Stoltenberg's office. For now, he will work from the defence ministry in another area of Oslo and cabinet meetings will be held in a mediaeval fort near the waterfront. It is not clear whether the 17-storey prime ministry building will be rebuilt or torn down.
"I am glad to be back in my office ... to be able to resume the more normal work functions," Administration and Church Minister Rigmor Aaserud told reporters.
Her office, in a government complex, was little damaged. In Mr. Stoltenberg's building, which took the brunt of the car bomb blast, curtains flapped from a host of broken windows.
Mr. Stoltenberg has won high opinion poll ratings from voters for his handling of the crisis, with about 80 per cent of Norwegians reckoning he has performed "extremely well", according to a survey published in the daily Verdens Gang.
The prime minister, who knew some of the victims, has caught the national mood, urging his compatriots in a voice often cracking with emotion to unite around democratic values.
Norwegians, unused to violence in a quiet country of 4.8 million, must now struggle with how to improve security without jeopardizing the freedom and openness of their society.
On Tuesday night police destroyed an explosives cache found at a farm rented by Mr. Breivik, some 160 kilometres north of Oslo. They believe he made his bomb using fertilizer which he had bought under the cover that he was a farmer.
After the bombing, Mr. Breivik, 32, drove to an island hosting a youth camp of the ruling Labour Party and coolly shot dead 68 people, mostly youngsters, before surrendering to armed police.
Mr. Breivik's lawyer, Geir Lippestad, said his client was probably a madman, but it was too early to say if the loner and computer game enthusiast would plead insanity at his trial.
Mr. Breivik has confessed to his actions, but denied guilt, saying he was part of a network with two cells in Norway and more abroad that was fighting to save European "Christendom" from the spread of Islam and the danger of multi-culturalism.
But police believe Mr. Breivik probably acted alone in staging his assaults, which have united Norwegians in revulsion.
"So far we don't have any evidence of the cells, neither in Norway or in Britain," Janne Kristiansen, head of the PST security police, told the BBC. Mr. Breivik's online manifesto referred to a secret meeting in London in 2002 to found a "Knights Templar" group to drive Islam out of Europe.
"I would be surprised if this person was insane," Ms. Kristiansen said. "I mean he's calculating, he's focused, he's been going on with his plan for years, and this is not what I have learnt a person who is insane will do."
Flowers left by Norwegians to show their grief for Mr. Breivik's victims decked Oslo's main thoroughfare, Karl Johans Gate. Police say about 200,000 people, a third of the city's population, turned out for a commemorative rally on Monday.
Police reopened some streets around the blast site in Oslo and vendors gradually reopened for business.
Workers at a corner store about 150 metres away have painted the plywood boards put up in place of blown-out windows.
"Fixing the glass (windows) will take a week or two and the wood looks better painted," said deputy store manager Aykan Bastas. "We will fix it up nicely, just like before."
Mr. Breivik, who was remanded in custody for eight weeks on Monday, has been charged under the terrorism act, which carries a maximum penalty of 21 years in jail, but the authorities are considering whether to charge him with crimes against humanity.
"We are looking into it," police attorney Christian Hatlo said when asked about possible crimes against humanity charges, which carry a maximum prison sentence of 30 years.
In both cases, sentences can be extended if there is a risk of repeat offences, so Mr. Breivik could be behind bars for the rest of his life. His lawyer has said his client expects this.
Mr. Hatlo said it was not clear if legislation to cover crimes against humanity was applicable in Mr. Breivik's case.