Geir Lippestad, the defense lawyer for the Nowegian mass killer Anders Behring Breivik, said in a statement on Tuesday that his 32-year-old client, who killed at least 76 people on Friday in Oslo and on the island known as Utoeya, is "insane."

Anders Behring Breivik, 32, who according to local media was arrested by police after the shooting in Utoeya, is seen in this handout photo released to AFP on July 23, 2011. [Xinhua/AFP Photo]

There are indications that he is a madman, Breivik told reporters at a packed press conference.

"The whole matter suggests that he is insane. He thinks he is in a war, and that when you are at war, you can do things like this," said Lippestad.

The lawyer said that he found it hard to describe Breivik, but he appears to be a cold person. "He is not like any of us. He is in a bubble," he added.

Breivik was surprised that he succeeded in carrying out his plan to attack on Friday because he felt that he could have been stopped before he reached Utoeya, where killed 68 young people in a shooting spree, according the lawyer.

Breivik "sees himself as a warrior, and is proud to have started a war that others will continue," said Lippestad.

The defendant claimed that there are "two cells" operating in Norway in addition to a number of others abroad, but he refused to say anything about them except that they can plan attacks, according to the lawyer.

Norwegian investigators said that Breivik might be bragging about his acting along with a network.