NORWEGIAN police said today the suspect in the twin attacks that left at least 91 dead was “cooperating” with investigators and “wants to explain himself”.

They added that the man, arrested after seven were killed in a bomb attack in Oslo and 84 were shot dead in a two-hour shooting spree on the nearby island of Utoya overnight, is a “Christian fundamentalist”.

Norway’s Prime Minister Jens Stoltenberg said today the twin bomb and shooting attacks were a “national tragedy” that had turned a youth paradise island into hell.

“Never since the second World War has our country been hit by a crime on this scale,” Mr Stoltenberg said at a media conference today.

The twin attacks began with an explosion at about 3.30pm local time on Friday in Oslo’s Government quarter near the Prime Minister’s office.

The second attack – a shooting rampage – took place on Utoya, where the Labour Party-affiliated Workers’ Youth League was conducting a summer camp.

“For me, the island was my youth paradise and now it’s been changed to a hell,” Mr Stoltenberg said.

The Prime Minister said he had visited hospital staff tending to the injured in Oslo, and he would later travel to Utoya to meet those affected by the tragedy.

He added that all flags across the country would fly at half-mast today.

Mr Stoltenberg declined to discuss the motive for the attacks.

“It’s too early to comment,” he said. “The police have just started the investigation. One man is arrested and I think we’ll wait till we see more results of the investigations before we comment.”

The Minister of Justice Knut Storberget said today government talks over the next few days would focus on how the nation could prevent further such attacks.

“We are able to have political discussion without having police protection, to engage in politics without being afraid,” he said. “We are an open, safe society where political debate can go on.”

While Mr Storberget did not name the man arrested in connection with the attacks, he assured Norwegians that those involved would be brought to justice.

Media reports have identified the man behind both attacks as 32-year-old Norwegian Anders Behring Breivik.

Of the 91 feared dead, at least 84 of the victims were killed on the island of Utoya, where a gunman dressed as a policeman opened fire on youngsters at a youth summer camp.

The accused gunman and suspect in the blast – Mr Breivik – was arrested at the scene and was in custody as the traditionally peaceful country tried to come to grips with the true horror that had befallen it.