Investigators asked the public to provide clues Monday to help find out who bombed a van driven by the wife of Navy Capt. Will Rogers. They refused to speculate the explosion was a terrorist reprisal for the U.S. downing of an Iranian jetliner.

After some 30 federal agents combed the area of the explosion and pored over the fire-gutted vehicle, the intersection was reopened early Sunday, FBI spokesman Gene Riehl said. The van was towed from the area late Saturday and three drums filled with bomb fragments and other debris have been sent to Washington for analysis."We decided that we're really into an intensive investigative effort and we can't talk about anything," Riehl said.

Thomas Hughes, head of the FBI office in San Diego, said in a statement that investigators from the FBI, Naval Investigative Service, Bureau of Alcohol, Tobacco and Firearms, San Diego Police Department and San Diego County Sheriff's Department "are all working very hard together to resolve the matter."