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.
Syrian forces foiled an attempted suicide car bombing with 1,200 kg (2,640 pounds) of explosives in the northern city of Aleppo on Friday, state television said, a day after two bombs in the capital Damascus killed at least 55 people.
The would-be bomber was killed in the al Shaar district of Syria’s largest city which, like Damascus, has seen increasing street protests against President Bashar al-Assad and rising levels of bloodshed after months of relative calm.
Twin bombings in southern Damascus killed 55 people and wounded more than 300 on Thursday, the deadliest attacks since the uprising against Assad erupted 14 months ago, inspired by revolts against autocratic rulers elsewhere in the Arab world.
The blasts further undermined a tattered ceasefire agreement repeatedly violated by the army and rebels since it was brokered by international mediator Kofi Annan four weeks ago. The deal has been overseen by nearly 150 unarmed U.N. observers in Syria.