The plot had parallels with Anders Behring Breivik, the Norwegian who set off a bomb in Oslo last year and then went on a gun rampage on a nearby island, killing a total of 77 people.
“The would-be bomber did not hide his fascination with Breivik. This should not be ignored,” Tusk told a news conference.
The prime minister said that investigators had found practical connections to Breivik too: the Norwegian bought bomb components in Poland, he said, and an analysis of his contacts helped lead Polish intelligence to the suspect.
Authorities in Norway said they had been in touch with their Polish counterparts but gave no details.
Briefing reporters in the Polish capital, prosecutors said the suspect had assembled a small arsenal of explosive material, guns and remote-controlled detonators and was trying to recruit others to help him.
A video recording taken from the suspect, who has not been publicly identified, showed what prosecutors said was a test explosion he conducted, sending up a huge cloud of dust and leaving a large crater in the ground.
“He claims that he was acting on nationalistic, anti-Semitic and xenophobic motives,” prosecutor Mariusz Krason said.
“He believed the situation in the country is going in the wrong direction, described the people ruling Poland as foreign and said they were not true Poles.”
“He carried out reconnaissance in the neighborhood of the Sejm (parliament). This building was to be the target of the attack,” Krason said.