Confessed mass killer Anders Behring Breivik was ordered to remain in pre-trial detention for eight weeks Monday during a closed court hearing in which he was cut off from making statements irrelevant to the case, a judge said.

The 32-year-old right-wing extremist has confessed to setting off a bomb in downtown Oslo and massacring dozens at an island youth camp outside the city, killing 77 people on July 22.

The Oslo District Court approved a police request to keep Breivik in custody on terror charges for another eight weeks — four of them in solitary confinement — as they prepare a formal indictment.

Judge Anne Margrethe Lund said she stopped Breivik "on a few occasions" when he tried to make statements during the court hearing, his third since being arrested following the carnage on Utoya island.

"He wanted to communicate something to the court. It wasn't relevant for the decision that was to be made today and therefore he wasn't allowed to say anything further," Lund told reporters after the hearing.

Breivik's defense lawyer Geir Lippestad also told reporters that his client tried to address the court but declined to give details, citing a gag order.

The ruling means police can continue to hold Breivik in custody until Nov. 14 when a new detention hearing will be held. But they can only hold him in isolation until Oct. 17 because decisions on solitary confinement must be reviewed every four weeks.