Norway’s prime minister on Wednesday promised a security review after a mourning period for at least 76 people killed in bombing and shooting attacks Friday that have traumatized the nation.

Meanwhile, Norwegians tried to restore some sense of normalcy five days after the bloodshed, despite a security alert forcing the evacuation of Oslo’s central station.

Prime Minister Jens Stoltenberg said at a news conference that many European intelligence services had joined the investigation into Norway’s bloodiest massacre since World War II.

Police “organization and capacity will be part of an evaluation,” Stoltenberg said, adding that he expected the attacks to stimulate, rather than dampen, political engagement in Norway.

“I believe the result of this will be more participation, more political activity,” Stoltenberg said. “Our commitment to our core values will grow stronger.”

Anders Behring Breivik, a far-right extremist, has admitted to the bombing in Oslo and the shooting rampage on a nearby island. But he has given varying accounts of his actions, first saying that he operated alone and then telling a judge that he was part of a wider network.

Norway’s domestic intelligence chief said she believed Breivik was a lone operator, and she contested an assertion by his attorney Tuesday that his client was probably insane.

Oslo’s main station was evacuated Wednesday after a suspicious suitcase was found on a bus. Police said later that it was harmless.

In another false alarm, police retracted a search alert for a man they suspected of sympathizing with Breivik, saying that in fact they wanted to detain a mentally ill man with no link to the self-described killer.

Stoltenberg has won high ratings in public opinion polls for his handling of the crisis, with about 80 percent of Norwegians saying that 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 reflected the national mood, urging his compatriots in a voice often cracking with emotion to unite around democratic values.

“Yes, I have cried,” he said of his personal reaction.

Norwegians, unused to violence in their quiet country of 4.8 million, must struggle with how to improve security without jeopardizing the freedom and openness of their society.

“Our challenge will be to reconcile those two things,” Stoltenberg said, denying that Norwegians had been naive. “It is very important to distinguish between naivete and openness.”

He said he welcomed a debate about security measures and the police response to the emergency. Some critics have accused the police of taking too long to reach the island northwest of Oslo where Breivik shot 68 people, mostly youngsters at a summer camp for the ruling Labor Party’s youth wing.

Stoltenberg said Norway has special forces trained to deal with violent attacks, even if the country had not experienced them before.

“We are even more aware of any dangers now than before the attack,” he said. “But, in general, Norwegians want . . . to defend themselves against violence by showing they are not afraid of violence.”

— Reuters