LOS ANGELES, Aug. 31 (Xinhuanet) -- Four men, including the head of a prison-based Islamic extremist group, were indicted Wednesday for allegedly plotting terror attacks on military facilities and other targets in southern California.

    The indictment alleges that Jamiyyat Ul-Islam Is-Saheeh founder Kevin James and three California men, Ear Washington, Gregory Patterson and Hammad Samana, conspired "to levy a war against the government of the United States through terrorism."

    Prosecutors said the attacks were to be financed through a string of armed robberies of gas stations.

    Washington, who was paroled from a California state prison in November, allegedly acted at the urging of James, who is still serving a state sentence.

    Washington allegedly recruited the two other men, and the defendants had been "on the verge of launching the attacks," which "had the potential to cause significant bloodshed," said US Attorney Debra Yang.

    James, 29, preached that members of his group, also known as JIS, had a duty to violently "attack any enemies of Islam or 'infidels,'" including the US government and supporters of Israel,the indictment states.

    "We have a tendency to think of terrorism as something that's merely foreign to us, and this is really a stark reminder" that it can be homegrown, Yang told reporters at a press conference here.

    According to authorities, Samana, who immigrated to the United States from Pakistan and is a legal permanent resident, is the only one of the four not born in America.

    The six-count indictment also includes charges of conspiracy to kill members of the military, conspiracy to kill foreign officials, conspiracy to use a firearm in a crime of violence, interference with commerce by robbery and use of a shotgun during a gas station robbery in early July.

    If convicted of all the charges, the defendants face life prison sentences.

    Authorities said the investigation began nearly two months ago when local police received a tip concerning a string of gas station robberies in the Los Angeles and Orange counties that began May 30.

    More than 500 investigators from 25 different agencies were involved in the case, officials said. Enditem