An "animal rights extremist" from Berkeley, Calif., was added to the FBI's "Most Wanted" list of terror suspects, federal agents said Tuesday.

Daniel Andreas San Diego, a 31-year-old computer specialist, has been on the run since 2003 and is wanted in two bombings that year of corporate offices in California, said Michael J. Heimbach, an assistant director of the FBI's counterrorism division.

"He is a known animal rights extremist," Heimbach told reporters Tuesday at a Washington, D.C., news conference.

He added that San Diego set an improvised explosive device in the bombings that caused "extensive property damage and economic hardship."

"The investigation revealed that metal nails were used in the construction of the device to create a more forceful effect," Heimbach said.

Click here for Daniel Andreas San Diego's FBI 'Most Wanted' poster.

It's the first time an accused domestic terrorist has been put on the "Most Wanted List," which includes Usama bin Laden, Ayman Al-Zawahiri, and Adam Yahiye Gadahn, among others. San Diego is the 24th person on the list.

Gadahn, another American on the list, grew up in California but later moved to Pakistan and is wanted for acts authorities say he committed overseas, as an alleged translator and consultant for Al Qaeda.

San Diego is the only 'Most Wanted' terror suspect sought for attacks he allegedly committed in the United States.

San Diego has a tattoo that proclaims, "It only takes a spark," according to authorities.

Click here to read's original WANTED story on Daniel Andreas.

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 damage 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 $250,000 reward for information leading to his capture, five times the reward amounts offered for other so-called eco-terrorists wanted in the U.S.

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 Qaeda chief bin Laden is on both.

The Associated Press contributed to this report.