Eight people, including four members of an anti-government militia, were arrested on weapons and explosives charges and accused by the FBI on Monday of arming themselves for a clash with the government.
The FBI gave no details of what the defendants, seven men and one woman, were allegedly planning. But it said the arrests were not related to Saturday's bombing at an Olympic park in Atlanta.
The eight were arrested in a roundup over the weekend, five of them as they took part in a class in Bellingham, about 80 miles north of Seattle, on how to use explosives. The roundup came after the group was infiltrated by FBI agent Ramon Garcia.
All eight were charged with conspiracy to make and possess explosive devices. Four also were charged with making explosive devices.
Their objective was "to make and possess destructive devices including, but not limited to pipe bombs," FBI agent Burdena Pasenelli said.
The eight planned to use the devices "to arm themselves for what they believed would be an eventual confrontation with the United States government or the United Nations," according to court documents.
Pasenelli said agents are investigating whether the defendants had any tie to four recent bombings in the Spokane area. No one was injured in any of those blasts.
Pasenelli said four of the people arrested were members of the anti-government Washington State Militia. Among them was the militia's founder and former executive director, John Pitner. Four others belonged to a Seattle-area group referred to by Pitner as "Freemen," according to court papers.