SPOKANE, Wash. (AP) - A bomb left along the route of a Martin Luther King Jr. Day parade was a sophisticated explosive that had a remote detonator and the ability to cause many casualties, an official familiar with the case said Wednesday.
The bomb, which was defused without incident on Monday, was the most potentially destructive he had ever seen, said the official, who spoke on condition of anonymity because he is not authorized to release information about the investigation.
The FBI said it has no suspects in the case and has asked the public for help in identifying anyone who might have been seen in the downtown area where the bomb was found.
The FBI on Wednesday declined to reveal any details about the bomb, which was spotted by three city employees about an hour before the parade was to start, said Frank Harrill, special agent in charge of the Spokane office. The employees looked inside, saw wires and immediately alerted law enforcement, and the parade was rerouted.
The FBI received no warnings in advance and no one has claimed responsibility for planting the bomb, Harrill said.
The bomb was contained inside a black backpack made by Swiss Army, and the FBI released a photo of the backpack as it sought information from the public. Also released were pictures of two T-shirts found in the pack. There was a gray T-shirt with writing for the Stevens County Relay for Life race last June. Stevens County is just north of Spokane County. The other dark T-shirt said Treasure Island Spring 2009.
The FBI and local officials have praised as heroes the city workers who spotted the backpack and quickly called police. Police were also hailed for immediately deciding to reroute the parade. The several hundred marchers, including many children, were not told why the route was changed.
Harrill said the FBI has received some leads since offering a $20,000 reward for information on Tuesday. But the agency can't discuss the leads publicly, he said.
There were no notes in the backpack, which has been shipped to an FBI lab in Quantico, Va., Harrill said.
Investigators are also seeking anyone who took photographs or video in the area between 8 a.m. and 11 a.m. on Monday.
Investigators have said the bomb was carefully placed on a metal bench with a brick wall behind that would have directed shrapnel toward Main Street, where marchers were expected to pass.