For the first time, an accused domestic terrorist is being added to the FBI's list of "Most Wanted" terror suspects.

Daniel Andreas San Diego, a 31-year-old computer specialist from Berkeley, Calif., is wanted for the 2003 bombings of two corporate offices in California.

Authorities describe San Diego as an animal rights activist who turned to bomb attacks and say he has tattoo that proclaims, "It only takes a spark."

San Diego would be the 24th person on the list, and the only domestic terror suspect.

The move to add a domestic, left-wing terrorist to the list comes only days after the Obama administration was criticized for internal reports suggesting some military veterans could be susceptible to right-wing extremist recruiters or commit lone acts of violence. That prompted angry reactions from some lawmakers and veterans groups.

An arrest warrant was issued for San Diego after the 2003 bombings in northern California of the corporate offices of Chiron Corp., a biotechnology firm, and at Shaklee Corp., a nutrition and cosmetics company. The explosions caused minor damages and no injuries.

A group calling itself "Revolutionary Cells" took responsibility for the blasts, telling followers in a series of e-mails that Chiron and Shaklee had been targeted for their ties to a research company that conducted drug and chemical experiments on animals.

Officials have offered a US$250,000 reward for information leading to his capture, five times the reward amounts offered for other so-called eco-terrorists wanted in the US.

In February, the FBI announced San Diego may be living in Costa Rica, possibly working with Americans or people who speak English in the Central American country.

Law enforcement officials describe San Diego as a strict vegan who possesses a 9mm handgun. On his abdomen, he has images of burning and collapsing buildings.

The FBI's "Most Wanted" terrorist list is distinct from the much longer-running "Ten Most Wanted" list. Al-Qaida chief Osama bin Laden is on both.