Norway's justice minister says the government is appealing the Oslo district court's ruling that Norwegian authorities had violated the human rights of mass killer Anders Behring Breivik.

Anders Anundsen says the government "disagrees" with the April 20 ruling that said the isolation of Breivik, who faces prison for killing 77 people in a bomb-and-gun massacre in 2011, breaches the European Convention on Human Rights.

Anundsen said Tuesday that further details about the government's decision would be released within days.

Last month, Breivik, 37, had sued the government, saying his isolation from other prisoners, frequent strip searches and the fact that he was often handcuffed had violated his human rights. He is held in solitary confinement in a three-cell complex where he can play video games, watch TV and exercise.