Judge Torkjel Nesheim seen in an Oslo court house in the case against Breivik for attacks that killed 77 [Reuters]

A gunmen who killed 77 people in attacks in Norway on July 22 has acknowledged carrying out the massacre but refused to plead guilty in his first public court appearance since the attacks.

Anders Behring Breivik, speaking on Monday at a court just two blocks from where he detonated a huge home-made bomb before shooting 69 people at the ruling political party's youth summer camp, also rejected the court's authority to hear his case.

"I am a military commander in the Norwegian resistance movement and Knights Templar Norway," Breivik told the court. "Regarding the competence [of the court], I object to it because you received your mandate from organisations that support hate ideology [and] because it supports multiculturalism."

"I acknowledge the acts but I do not plead guilty," Breivik said.

The killings shattered a nation known for its open society, peace and relative prosperity, sparking a debate about immigration and security.

Breivik, speaking at a court picketed by a group of protesters holding a banner that read "No speakers' platform for fascists", attempted to address survivors and victims' relatives but the court denied his request.

The hearing, required under Norwegian law to keep a suspect in prison before trial, was Breivik's fourth, and as expected, the court decided to keep him in custody.

It was the first opportunity for the media, surviving victims and victims' relatives to hear Breivik, 32, speak publicly.

He will likely remain in prison until he goes to trial, probably in the first half of 2012.

Some 120 people were admitted to the courtroom, while hundreds of others squeezed into overflow rooms equipped with video links.

Source: Agencies