A federal grand jury indicted two Southern California men Wednesday with conspiracy to smuggle surface-to-air missiles into the United States. Such missiles are designed to bring down aircraft.

The U.S. attorney's office said the charges against Chao Tung Wu, 51, of La Puente and Yi Qing Chen, 41, of Rosemead marked the first time a 2004 anti-terrorism statute has been used. The statute calls for a mandatory minimum sentence of 25 years and the possibility of life in prison without parole if convicted.

The men have been in custody since August when they were arrested as part of Operation Smoking Dragon, a federal undercover investigation into smuggling operations in Southern California. The men were originally charged with conspiracy to distribute methamphetamine and Ecstasy and importing millions of counterfeit cigarettes.

The men were previously ordered held without bond. An arraignment hearing on the new charges was scheduled for Monday.

"Today's indictment shows a willingness of the smugglers to acquire practically anything for importation, no matter how dangerous or destructive," U.S. Attorney Debra Wong Yang said in a statement.