A Polish security agency said Wednesday that 19 people have been arrested across the country on suspicion of producing and possessing explosives.
The Internal Security Agency said the arrests were part of a wider investigation into the illegal production and sale of explosives that was launched after Norway asked Poland to investigate people with links to mass killer Anders Behring Breivik, who has confessed to two attacks that killed 77 people in July in Norway.
The agency said the arrests were also the result of an analysis of a manifesto that Breivik had posted on the Internet.
In the summer, Poland was asked to provide information on a man who was mentioned by Breivik as a possible source of substances that could be used in the production of explosives. An investigation revealed that Breivik had bought small quantities of two different chemical substances from an online vendor in Poland.
The vendor, Lukasz Mikus, admitted in August that Breivik ordered at least 50 kilograms (110 pounds) of aluminum powder from his company early this year and appeared to be a legitimate trade representative from a Norwegian company.
The agency did not say Wednesday whether Mikus was among those arrested.
The agency statement said, however, that large quantities of explosives were seized on Tuesday and Wednesday during a search of some 100 homes and houses and dozens of cars and garages across the country. The search was carried out by the agency, police, border guards and firefighters.
A few dozen people, who were obtaining chemicals at a warehouse near the western city of Poznan, are suspected of using the substances to make explosives.