Breivik killed 77 people in Norway’s worst peacetime atrocity in July 2011.

He killed eight with a car bomb in Oslo and then gunned down 69, most of them teenagers, at a Labour Party youth camp.

Hungarian police said the man, who was not named, had uploaded several posts to a video-sharing portal in which he outlined plans to commit mass killings in an unspecified location.

Police said the suspect, who spoke mostly in Norwegian and in some cases English, said he aimed to outdo Breivik’s killings.

“I can strike anywhere … Airport, railway terminal, nothing can be a problem … I will destroy the innocent,” police quoted the man as saying in some of the videos.

The man, detained by counter-terrorism forces last Wednesday and formally arrested on Saturday, has been convicted for various cases of violence and sex crimes in Norway, Hungarian police said, citing information received from their Norwegian counterparts.

They did not elaborate further on his past crimes.

The suspect is being held at a forensic mental institution, police said.