Device capable of inflicting 'multiple casualties'

A bomb left in a backpack on the route of a Martin Luther King Day parade in Spokane, Washington, has been described as being in the "realm of domestic terrorism" by the FBI.

The bomb was found on bench Monday morning at the northeast corner of North Washington Street and West Main Avenue in the city's downtown core. Spokane police were alerted to its presence before the parade -- which was attended by some 1,000 people -- got underway.

The parade was rerouted away from the site. A robot and a hazmat unit were used to defuse the device.

The FBI would not say how the bomb was made, or whether it was connected to a triggering device of any kind, but the bureau said the bomb was capable of inflicting "multiple casualties."

"You could describe it as an improvised destructive device ... or improvised explosive device," FBI special agent Frank Harrill told NBC News.

“Clearly, the timing and placement of a device -- secreted in a backpack -- with the Martin Luther King parade is not coincidental," Harrill told the Spokesman-Review. "We are doing everything humanly possible to identify the individuals or individual who constructed and placed this device."

Harrill added: “I think the link to the Martin Luther King celebration and march is inescapable. ... At that point, it falls directly in the realm and sphere of domestic terrorism. Clearly, there was some political or social agenda here."

Coming nine days after Rep. Gabrielle Giffords of Arizona was shot in the head in an act many said was politically motivated, the news of a bomb at an MLK Day parade will likely heighten concerns that US politics are treading dangerously close to violent waters.

The FBI has offered a $20,000 reward (PDF) for information leading to a suspect in the incident. The bureau also released photos of the backpack -- a weather-beaten Swiss Army brand bag -- as well as pictures of two items found inside, one a T-shirt marked with the words "Treasure Island Spring 2009" and another with the words "Stevens County Relay For Life, 2010."

Agents hope the items may lead to a tip from the public. The FBI are asking members of the public to come forward if they saw an individual carrying such a backpack between 8 a.m. and 9:25 a.m. in downtown Spokane on Monday morning.