FBI video shows powerful explosion at San Diego courthouse

The FBI hopes anyone with information about Sunday's explosion will contact investigators after seeing the video, said spokesman Darrell Foxworth.

"We want people to see the potential harm this could have caused to anyone in or around the building," Foxworth said. "If anyone was under the impression that this was done simply to cause property damage, this shows that was not the case."

The bomb caused significant damage to the lobby and forced the courthouse to close for one day, but no one was injured.

The FBI recovered more than 100 nails and shrapnel as far as two blocks from the courthouse, Foxworth said. Investigators believe the bomb may be linked to a blast April 25 that shattered the glass door of a FedEx building in San Diego

Dogs have traced the footsteps of the attackers to a waterfront mall about six blocks southwest of the courthouse, Foxworth said.

The FBI has said surveillance video shows people in the area shortly before the explosion but has declined to release that video. The agency has no suspects, Foxworth said.