An Orange County man who had fought with Syrian rebels against the Assad regime was arrested Friday morning as he tried to leave the U.S. with a fake passport to fight for al Qaeda against U.S. soldiers overseas, said authorities.

Twenty-four-year-old Sinh Vinh Ngo Nguyen of Garden Grove, also known as Hasan Abu Omar Ghannoum, was stopped at a bus station in Santa Ana, Calif. at 7:30 a.m. by members of the Los Angeles Joint Terrorism Task Force and arrested on suspicion of providing material support to al Qaeda.

According to a grand jury indictment, Nguyen, a U.S. citizen, lied about his name, his date of birth, and his place of birth on a passport application in August, and also falsely answered no when asked if he’d ever applied for a passport previously.

Nguyen is charged with one count of making false statements to obtain a passport and one count of attempting to provide material support to a foreign terrorist organization.

According to law enforcement officials, Nguyen traveled to Syria last year to fight with rebels against the Assad regime. When he returned, he allegedly expressed a desire to go to Pakistan and join up with al Qaeda. He allegedly met someone he thought could help him, but that person turned out to be working undercover for the U.S.

Federal officials said Nguyen told the person helping him that he wanted to go overseas, fake his own death and get a new identity so he join al Qaeda and fight against U.S. soldiers. He allegedly gave the person photos, got a new fake passport, and was arrested when he tried to use that passport to leave the country.

Nguyen pleaded not guilty in U.S. District Court in Santa Ana on Friday afternoon. If convicted on both counts, he faces up to 40 years in federal prison.

At the courthouse, his mother, Hieu Nguyen, told The Associated Press that he had converted to Islam in the past year.

Last year, four Riverside County, Calif. men -- Sohiel Omar Kabir, Arifeen David Gojali, Ralph Kenneth Deleon and Miguel Santana Vidriales -- were charged by federal prosecutors in connection with a purported plot to join al Qaeda and the Taliban to carry out “violent jihad” against American soldiers and military bases in Afghanistan.

FBI agents alleged that Kabir, who was arrested in Kabul, radicalized Deleon and Santana and along with Gojali planned an assault on American troops using rifles and explosives. Federal authorities also alleged that the foursome, who are awaiting trial, intended to attack Americans in the U.S. if they returned. The FBI said three of the men conducted “preliminary training in Southern California at firearms and paintball facilities.”

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