FBI agents are checking if there's a link between a Western Washington explosives ring and unsolved bombings and bank robberies in Spokane.
No firm connections are known, but the possibility hasn't been eliminated, FBI officials said Monday.
Nine suspects, including four members of the Washington State Militia, are under arrest in Seattle on federal conspiracy and explosive charges.
The arrests occurred Saturday afternoon while the suspects were attending a bomb-making class in Bellingham, said Burdena Pasenelli, FBI special agent in charge.