They asked for the public's help in tracking down Daniel San Diego, 33, who formerly lived in Schellville in Sonoma County.
San Diego has been charged in federal court in San Francisco with bombing the headquarters of Chiron Corp. in Emeryville on Aug. 28, 2003, and Shaklee Corp. in Pleasanton on Sept. 26, 2003.
No one was hurt but minor damage resulted when the homemade bombs exploded in early morning hours.
An animal rights group called Revolutionary Cells claimed responsibility for both blasts and said the reason for the attacks was that the companies did business with Huntingdon Life Sciences, a New Jersey firm that tests products on animals.
FBI spokesman Julie Sohn said in San Francisco today that the agency received a tip resulting from the "America's Most Wanted" television program that San Diego may be in the area of Northampton, Massachusetts.
The FBI has offered a $250,000 reward for information leading to the arrest of San Diego, who was placed on the FBI's Most Wanted Terrorist List in 2009.
Anyone with information about his whereabouts is asked to call the FBI in San Francisco at (415) 553-7400 or Boston at (617) 742-5533.
San Diego is a vegan with computer networking expertise and is 6 feet tall, weighs 160 pounds and has brown hair and brown eyes, the FBI said.
