Norwegian mass murderer Anders Behring Breivik has told a court he would fight "to the death" for Nazism.

The 37-year-old right-wing extremist, who is suing the Norwegian authorities over his prison conditions, claimed the state had been "trying to kill me for five years" by keeping him in isolation following the 2011 massacre in which he killed 77 people.

The government has rejected his claims.

On the second day of the case, brought by Breivik, he obeyed a judge's order not to make a Nazi salute, as he had at the opening hearing.

The gesture fuelled concerns he would use the proceedings as a platform for his extremist views.

Although Breivik has the run of three cells and access to facilities, including a television and games console, his lawyer has called his almost five-years in solitary "inhuman" and complained his letters are censored.

TV broadcast

The case is being broadcast on Norwegian television, but his testimony is not being aired out of respect to the families of the victims and the survivors, and to prevent him from sending any coded messages to his supporters.

Breivik is serving a maximum 21-year sentence for killing eight people in a bomb attack outside a government building in Oslo in July 2011, then murdering another 69 people, most of them teenagers, in a shooting rampage at a

Labour Youth camp on the island of Utoya.

The killing spree lasted more than an hour as he methodically stalked and killed his victims.

He blamed Norway's dominant political party for the rise of multiculturalism.

Breivik's prison sentence can be extended if he is still considered a danger to society.