24/04/2012 10:35 BST | Updated 24/04/2012 10:45 BST

Breivik Trial: Security Guard Describes 'Terrible Destruction' Of Oslo Bombing

Survivors of the Oslo bombing carried out by right-wing extremist Anders Breivik have given harrowing evidence at his trial.

Eight people died and another nine were very seriously injured in the explosion, which preceded Breivik's gun rampage at a youth political camp on the nearby island of Utoya.

Security guard Tor Inge Kristoffersen told the court in Oslo about the moment he saw the bomb explode on CCTV.

He said that he saw a man in a guard's uniform park a van, get out and disappear.

He zoomed in with a camera on to the car's number plate when the bomb inside it exploded.

"There as a deep rumbling, the entire block shook and the ceiling bent like water," he said.

"I saw dead people outside and terrible destruction."

Breivik has previously described how he had intended to bring down the government building, but witnesses told the court a bomb around twice the size of the one Breivik exploded would have been needed to collapse the structure.

Kristoffersen described how one of his colleagues had died in the explosion, and several others were not able to continue working because they were so disturbed by the experience.

Above: the aftermath of the blast in Oslo which killed eight people

Also giving evidence on Tuesday, the head of police operations, Thor Langli, described how the first reports after the blast described a man of "non-Nordic" appearance, which were later changed to a blond, white-skinned man.

He said this made him think there were two suspects at first.

But then, turning to Breivik, Langli added: "I could not imagine there being two people with so many crazy ideas."

Another witness, Ministry of Defence bomb expert Svein Olav Christensen, said that Breivik's bomb weighed 950kg.

He was at home outside Oslo when the blast occurred, but he travelled in to assess the damage for himself after hearing the explosion.

Christensen also described how police reconstructed the bomb based on Breivik's notes, and showed pictures of the massive explosion it created.

Later in court police witnesses delivered extremely graphic details of the victims and the injuries they sustained:

The families of those who died in Oslo cried and held hands as the details were read out before the court adjourned.

Throughout the trial Breivik sat impassively, according to reports, and did not show remorse.

In his final day of testimony on Monday, Breivik described the moment he spared a 21-year-old man he had the sights of his rifle, because he thought the boy looked similar to himself.

Breivik has admitted carrying out the bombing and a subsequent series of shootings on Utoya island which left 77 people dead. The trial centres on whether Breivik is insane, which will determine whether he spends at least 21 years in prison or is incarcerated in a psychiatric institution.