Spokane backpack bomb 'unusually sophisticated'

The FBI says a backpack bomb found along the Martin Luther King Day parade route in Spokane could have hurt many people. A bomb disposal unit safely defused the device Monday. Now the federal government has enlisted a joint terrorism task force to track down the would-be bomber.

The FBI's supervisory agent in Spokane says the feds and local police are running down "hundreds of leads." They're also asking for the public's help to figure out who placed a Swiss-army brand backpack containing a bomb on a downtown street corner bench.

Agent Frank Harrill says the FBI had no advance warning of a threat to the Martin Luther King Day march:

"I think a reasonable person can reasonably conclude that these events were linked."

Harrill declined to give specifics on how the backpack bomb was made, except to say it was clearly designed to inflict "multiple casualties." 

The Associated Press today cites a source familiar with the investigation as saying the device included a remote detonator and was unusually sophisticated.

Harrill says the would-be bomber left clues in the rucksack in the form of a two t-shirts. One says "Treasure Island - Spring 2009." The other is a souvenir from a cancer society fund-raising relay race.