Czech police arrested the 29-year-old man after raiding his apartment in the northeastern town of Ostrava, where they found an automatic weapon, a bomb and other explosive material.

"The components of the explosive device were operational," Ostrava police chief Radovan Vojta said on Saturday when announcing the week-old arrest.

The police chief said it was unclear who the suspect was planning to target, adding that the investigation was in its early stages.

The 29-year-old, whose name has not been released, was arrested on August 10. A quick-reaction force arrested him at his apartment after evacuating some 80 building residents.

Neighbors described the suspect as an unhinged gun-fanatic, but denied he was a right-wing extremist, according to the CTK news agency.

He had previously served a six-month suspended sentence for trying to detonate a homemade bomb at a gas station in Ostrava.

Specter of Breivik

The 29-year-old had used Breivik's name in emails, police said on Saturday.

Breivik detonated a bomb in front of Norwegian government buildings in Oslo on July 22, 2011, killing eight people.

He subsequently went on a shooting rampage at a Labour Party youth camp on the island of Utoya, where he killed 69 people, most of them teenagers.

Breivik's trial came to an end in June and he is scheduled to face sentencing on August 24. Although he has not pled guilty, he did admit to carrying out the attacks.

Questions remain over whether or not Breivik is mentally sane. If he is found to be sane, he would face a maximum sentence of 21 years in prison. Should he be declared criminally insane, he could be placed in psychiatric care for the rest of his life.

Breivik is a right-wing extremist who claims he carried out the attacks to protect Norway from multiculturalism.

slk/mz (AFP, dpa)