Oslo, Jul 24 (IANS): Anders Behring Breivik, the 32-year-old Norwegian who sprayed bullets at a youth camp killing 85 people and is also linked to a bombing in Oslo, has said his action was "gruesome but necessary", said his lawyer.

Breivik Saturday confessed to killing at least 85 people on Utoya Island Friday evening. Breivik is also believed to be linked to the Oslo bombing, which left seven people dead.

"He (Breivik) thought it was gruesome having to commit these acts, but in his head they were necessary," Breivik's lawyer Geir Lippestad told the Norwegian media.

Lippestad said the attack had been planned "for some while", reported BBC.

Charged with terrorism, Breivik is due to appear in court Monday.

The media report said that the police have not speculated on the motive. The bomb in Oslo targeted buildings connected to Norway's governing Labour Party while the youth camp on Utoeya island was also run by the party.

A 1,500-page manifesto, purportedly written by Breivik, shows his right-wing extremist views.

In it, he vows that a "European civil war" will lead to the execution of "cultural Marxists" and the banishing of Muslims, reported CNN.

The document gives details of Breivik's background and his plans to commit Friday's attacks.

"If you are concerned about the future of Western Europe you will definitely find the information both interesting and highly relevant," he wrote.

The document is titled "2083: A European Declaration of Independence". It is a date which Breivik believes that an European civil war will end with the execution of cultural Marxists and the deportation of Muslims.

This "civil war" would come in three phases, he claims.

Breivik states that he was moved to action citing his "government's involvement" in NATO's 1999 strikes during the Kosovo campaign.