Right-wing extremist Anders Behring Breivik, who killed 77 people in twin attacks in Norway last year, makes a far-right salute as he enters court for his trial, which begins on Monday. Breivik admitted to the massacres but pleaded not guilty in court to terror and murder charges, saying he was acting in self-defense. [Heiko Junge / Agence France-Presse]

The Norwegian militant who massacred 77 people last summer gave a clenched-fist salute, smirked at the court and said he acted to defend his country against Muslims on the first day of a trial that threatens to turn into a "circus" showcasing his far-right views.

Anders Behring Breivik, 33, has admitted setting off a car bomb that killed eight people at government headquarters in Oslo in July, then killing 69 in a shooting spree at a summer youth camp on an island organized by the ruling Labor Party.

The real question of the trial will be whether Breivik will be declared insane or criminal. While he risks staying behind bars for the rest of his life, the high school dropout has said being labelled insane would be a "fate worse than death".

Wearing a suit and loose tie, Breivik entered the court in handcuffs, which were taken off just before he was seated. He smirked several times as the cuffs were removed, put his right fist on his heart then extended his hand in salute.

"I do not recognize the Norwegian courts. You have received your mandate from political parties which support multiculturalism," Breivik told the court after refusing to stand when judges entered the courtroom.

"I acknowledge the acts but not criminal guilty as I claim self-defense," he added, seated in front of a bulletproof glass wall.

Occasionally suppressing a yawn and sipping water, he stared down at the indictment papers, following without visible emotion a list of his killings as the prosecutor read out each one. Some details were so graphic that Norwegian television bleeped out descriptions of the massacres.

The trial is scheduled to last 10 weeks and has raised fears that it could reopen wounds in Norway, a country that prides itself on its tolerant and peaceful society.

The "lone wolf" killer intends to say he was defending Norway against multiculturalism and Islam. He says the attacks were intended as punishment of "traitors" whose pro-immigration policies were adulterating Norwegian blood.

More than 200 people took seats in the specially built Oslo courtroom while about 700 attack survivors and family members of victims watched on closed-circuit video around the country.

"Today the trial starts, and it will be a tough time for many," survivor Vegard Groeslie Wennesland, 28, said outside the courtroom. "Last time I saw him in person he was shooting my friends."

Some Norwegians fear Breivik will succeed in making the trial, with about 800 journalists on hand, a platform for his anti-immigrant ideas. His defense team has called 29 witnesses to shed light on his world view. Norway's legal system gives defendants wide leeway to defend themselves as they wish, but judges can trim the witness list.

His proposed witnesses include Mullah Krekar, the Kurdish founder of Islamist group Ansar al-Islam, who was recently jailed in Norway for making death threats, and "Fjordman", a right-wing blogger who influenced Breivik. He is scheduled to testify for about a week, starting on Tuesday.

Breivik had been living with his mother in Oslo preparing for the attacks before renting a farm in order to make a fertilizer bomb.

On July 22, he set off the bomb in the center of Oslo before heading to the youth camp on Utoeya island in a lake 40 km outside the capital, gunning down his victims while police took more than an hour to get to the massacre site in the chaos following the blast.

Disguised as a police officer, Breivik managed to lure some of his victims out of hiding saying help had arrived. Other victims jumped into the lake, where he shot at them in the water.

Reading out the indictment, prosecutor Inga Bejer Engh spoke of the "panic and mortal fear in children, youths and adults" trapped on the island.

The prosecutors painted an image of a Breivik obsessed with the World of Warcraft computer game, prompting the judge to ask whether the game was violent. Breivik broke into a smile when the image of his online character was displayed.

Reuters