Norway gunman showed no mercy, boasting 'I'll kill you all'

A GUNMAN boasted "I'll kill you all" as he hunted teenagers on an idyllic island, shooting 84 of them dead after detonating a bomb.

Norway bomb

A GUNMAN boasted "I'll kill you all" as he hunted teenagers on an idyllic island, shooting 84 of them dead - just two hours after he detonated at least one bomb killing seven office workers.

The home-grown terrorist showed no mercy as he used at least two guns, including a machinegun and a pistol, to massacre the teens who were enjoying a summer camp on a Norwegian island.

Posing as a policeman, Right-wing extremist Anders Behring Breivik beckoned people towards him on the Utoya Island and without warning pulled weapons from a bag and opened fire.

In addition to the 91 killed, a further 90 were injured in Norway's bloodiest day since World War II. Shattered authorities warned the death toll could rise.

Early fears that international terrorists were responsible soon gave way to shock when it was discovered police had arrested a Norwegian man.

The killer continued his carnage for up to two hours, hunting down teens and adults on the island and chasing them into the icy waters as he fired on them, killing at least 84. Some pretended to be dead, but Breivik returned to some victims to shoot them again with a second weapon.

The two attacks formed the deadliest day of terror in Western Europe since the 2004 Madrid train bombings killed 191 people.

Breivik, 32, was described as a "madman" and was thought to have acted alone, targeting Norway's ruling Labour Party. The party's youth wing had organised the summer camp.

The trail of terror began at 3.26pm on Friday (11.26pm Friday Melbourne time) when a massive blast ripped through the government sector of Oslo's capital.

The bomb shattered several buildings including the 17-storey office of Prime Minister Jens Stoltenberg, who was working from home, and the Health Ministry.

It blew thousands of windows out of other buildings hundreds of metres away.

Victorians living in Oslo, witnesses and survivors of the evil events told of their horror at the nightmare sequence of events. Witness Jon Magnus said he saw dozens of people "screaming and crying, running around with blood coming out of wounds, covered in blood".

"I saw people lying lifeless on the side of the streets. I saw how the explosion had ripped off the facades of several buildings."

Ian Dutton, a New Yorker staying in a hotel nearby, said he was reminded of September 11, 2001.

He said people "just covered in rubble" were walking through "a fog of debris".

"It wasn't any sort of a panic," he said. "It was really just people in disbelief and shock, especially in a such a safe and open country."

Wangaratta expat Shane West heard the blast from the Oslo home he shares with his Norwegian wife and family. "I heard the blast and thought it was thunder until I saw the news," he said. "The whole country is in shock, it's just tragic.

"Oslo is such a small city and you feel so safe, but this is just unbelievable. It changes everything."

Less than two hours after the bombing, about 5pm, Breivik arrived at a jetty that services the holiday island of Utoya, a 40-minute drive northwest of Oslo.

Dressed in a black police uniform and bulletproof vest, he produced police identification and demanded to be taken by boat to the island. About 700 teenagers aged between 14 and 18 were camping on Utoya for the annual five-day youth activist conference.

One survivor said Breivik ordered people to come closer, then pulled weapons and ammunition from a bag and started shooting.

"At first we thought, is this balloons or someone kidding? Then we soon realised people were being shot," she said.

Many of the teens ran screaming into the freezing water and tried to swim 500m to the mainland.

Others hid in trees or the few buildings on the 500m-long island. Breivik stood on the shore and shot at the young teens swimming for their lives.

A police source said Breivik used automatic weapons and handguns.

As night fell and the search continued under lights, police raised the death toll to at least 80 and again to 84 when day broke.

"I saw young people running around, jumping into the water. We heard people screaming," said Kristine Melby, who lives on the mainland.

A 15-year-old girl told how she hid behind a rock the killer was standing on.

"I could hear his breathing from the top of the rock," said Elise, not giving her surname. Police helicopters and paramedics were held back from landing on the island because of the shooting.

Emilie Bersaas, 19, said she spent two hours hiding under a bed and called her family to tell them she was still alive.

"It is kind of unreal, especially in Norway. This is something we hear about in the US," she said.

Explosives were reportedly found in a van parked near the jetty and on the island.

Police captured Breivik and later searched his apartment and rural farm.

Mr Stoltenberg was due to speak to the youth camp today and former prime minister Gro Harlem Brundtland was scheduled to give a speech yesterday.

The Department of Foreign Affairs and Trade says 250 Australians are known to be in Norway but none are reported hurt or killed.