OSLO (Reuters) -Norwegian mass killer Anders Behring Breivik is suing the state for allegedly violating his human rights due to his being held in "extreme" isolation, and has filed another application for parole, his lawyer said on Friday. Breivik, now 44, is serving Norway's longest sentence, 21 years, which can be extended if he is still considered a threat. "He's suing the state because he has been in an extreme isolation for 11 years, and has no contacts with other people except his guards," Breivik's lawyer Oeystein Storrvik told Reuters.