Mass killer Anders Behring Breivik has claimed in court that Norway is violating his human rights by keeping him in isolation for murdering 77 people in 2011, but irritated the judge with a Nazi salute at the start of proceedings.
Clean-shaven and wearing a black suit, white shirt and golden tie, Breivik raised his right arm in a flat-handed Nazi-style salute on arrival at the court, slightly different from the outstretched arm and clenched fist he used in 2012.
His lawyer said Breivik considers himself a national socialist, or Nazi, and that the gesture was "the worst thing you can do in a courtroom".
Breivik later suggested it was an old Norse gesture, he said.
Judge Helen Andenaes Sekulic was not pleased either way, and told Breivik not to repeat the salute when court proceedings resume on Wednesday.
Appearing in public for the first time since he was sentenced in 2012, Breivik is claiming inhuman treatment by Norway, where he is serving 21 years for killing eight people with a bomb in Oslo and gunning down 69 others on an island nearby, many of them teenagers.
He has had just one visitor with whom he had physical contact - his mother, who was allowed into prison and gave him a hug shortly before she died of cancer in 2013.
Breivik's lawyer, Oeystein Storrvik, accused Norway of violating a ban on "inhuman and degrading treatment" under the European Convention on Human Rights by keeping the 37-year-old isolated from other inmates in a special three-room cell.
"There is no tradition in Norway for this type of isolation," he told the special court that will meet until Friday in a gymnasium at Skien jail, south of Oslo.
Norway rejects the charges of inhuman treatment.
"Breivik is a very dangerous man," said Marius Emberland, the lawyer representing the state, defending Breivik's conditions.
He said Breivik had been given some opportunities for interaction with others, including meeting volunteers to play chess, but had declined.
Another prisoner tried to attack Breivik last year, getting to within earshot.
When stopped by guards, the man shouted: "You are a killer, a child killer ... And I love my country," Emberland said.
Storrvik told Reuters he had advised Breivik against making the salute.
"He (Breivik) says he is a national socialist," he said.