Nineteen people in Poland were arrested on suspicion of providing explosives and bomb-making material to Anders Behring Breivik, the Norwegian terrorist who killed 77 people in Oslo in July. The arrests included twelve people from a Poznan-based company that sold explosive fuses over the Internet.

Poland's Internal Security Agency worked with Norway's police investigators to locate the Polish suppliers.

Breivik used the Polish fuses to detonate a bomb outside of government headquarters in Oslo. The blast killed eight people and injured dozens more. Shortly after the bombing, while police were evacuating the city center, Breivik opened fire on an island summer camp outside the city. He was wearing a police uniform when he attacked teenagers at a government-sponsored diplomatic retreat.

Breivik has admitted to killing 77 people, but pleaded not guilty to committing acts of terrorism, feeling that he didn't do anything morally wrong.

Police were able to locate many of Breivik's suppliers thanks to a 1,500-page manifesto he distributed before the attacks titled 2083: A European Declaration of Independence.

In 2083, Breivik detailed how to make explosives and where to get supplies, retelling his experiences in ordering chemicals such as aluminum powder and sodium nitrate. He paid for the supplies using PayPal.

The section on bomb-making reads:

To my surprise; I learned that my own country had at least one forum where the acquisitions of chemicals were discussed. And if my country, of 5 million, has it, then most countries will... Many of them order online (this works as very few of the compounds are illegal, just regulated) while others take road trips to f example Poland to get materials directly from small factories. These materials are then smuggled without problems to the country of destination. Many of these East-Block factories will sell most chemicals to you as long as you seem like a credible buyer (non-Muslim, non-extremist).

Breivik built his bombs on a rented farm 100 miles north of the Norwegian capital. Posing as a farmer, Breivik also reportedly bought fertilizer from a local store without incident. Five days after Breivik's arrest, Norwegian police detonated a cache of left-over explosive materials at the farm.

Police said in July that they are also investigating the existence of Breivik's survivor's kit. In the manifesto, Breivik said he hid weapons, ammunition, food and money to help him break out of prison, should he be captured alive.

In the manifesto, Breivik details his belief that the vast majority of European politicians and media figures are complicit in allowing Europe to be slowly conquered by Islam, and advocates an armed resistance that he continually compares to the Knights Templar, a Christian order that was formed to protect pilgrims during the Crusades.

Western Europe is today dominated by an alien system of beliefs, attitudes and values that we have come to know as 'Political Correctness,' Breivik wrote in 2083. Political Correctness seeks to impose a uniformity of thought and behaviour on all Europeans and is therefore totalitarian in nature...Political Correctness is Marxism, with all that implies: loss of freedom of expression, thought control, inversion of the traditional social order, and, ultimately, a totalitarian state.

Breivik, who has been in jail since July, was released from solitary confinement on Thursday. He is currently at the Ila prison awaiting trial.