In the same community of Auburn, a different type of homemade explosive was found and dismantled Sunday outside the Placer County Courthouse. No one claimed responsibility for either incident, the FBI said.
The FBI's Joint Terrorism Task Force is now investigating five incidents. The earliest occurred Dec. 27 and two have been claimed as the work of the Earth Liberation Front, a radical environmental group.
``We're certainly not discounting that they all could be related, but we haven't made that leap,'' said FBI spokeswoman Karen Ernst.
Five incendiary devices of still a different design were found before they could explode Jan. 12 at a commercial complex under construction in Auburn. There's been one arrest.
Three similar devices were used in an attempted bombing Dec. 27 at an upscale housing development in nearby Lincoln; the devices failed to ignite. Seven firebombs did ignite, however, Feb. 7 at an apartment complex in Sutter Creek, causing damage to four unoccupied units.
Graffiti at the Lincoln and Sutter Creek sites, and letters to newspapers after the Lincoln and first Auburn incident, claimed the bombs were the work of the ELF.
The letters said the attempted arson at the housing development was a statement against suburban sprawl; the Auburn office building was targeted as ``a statement against work and the horror of the (cubicle).'' The letters promised more actions ``every few weeks.''
The FBI says the ELF has caused more than $100 million in damage since 1996, including an arson at a five-story condominium under construction in San Diego in August 2003 that caused $50 million in damages.
