According to BBC
state that the 29-year-old was detained in the Czech city of Ostrava last week. An assault rife and explosives along with police clothing were found in his apartment.
Breivik had dressed as a police officer when he carried out a mass killing in Norway last year -- which saw him detonate a bomb in Oslo and then carry out a mass shooting dead of 69 in a youth camp on the island of Utoeya.
Police had searched his apartment on August 10 after they found the man had used the name 'Breivik' in an email correspondence. They were informed that he was going to detonate a large explosive device.
The authorities also said that he was carrying a remote control detonator when they arrested him, they don't know what his target was but said the explosives and weaponry that found in his apartment were functional.