A suspicious backpack on the route of Monday's Martin Luther King Day parade held a radio controlled pipe bomb that could have caused numerous casualties.

The bomb, found in Spokane, Wash., was first spotted on a bench by parade staff before Monday's scheduled event. Authorities rerouted the event while the local police department disposed of the bomb.

Police say the Spokane City-County Explosives Disposal Unit rendered the package safe. Officials have not said what the package may have contained, however further analysis by the FBI Tuesday showed the package to quite lethal.

Subsequent preliminary analysis revealed the backpack contained a potentially deadly destructive device, likely capable of inflicting multiple casualties, the FBI said.

No injuries were reported.