SAN DIEGO (AP) – Border Patrol agents in San Diego say they have caught 13 illegal immigrants wearing U.S. Marine uniforms.

Agency spokesman Michael Jimenez says Tuesday that the van was stopped at a border patrol checkpoint March 14 along Interstate 8. Jimenez says the van had a U.S. government license plate with an altered number. He says it’s not known where the group obtained the military uniforms.

The Naval Criminal Investigative Service is handling the investigation. Navy investigators referred calls to Washington, D.C., and no one could be reached for comment Tuesday afternoon.

Jimenez says two U.S. citizens who were with the immigrants were arrested on suspicion of alien smuggling. He says three of the illegal immigrants are being held in federal custody as witnesses and the others have been returned to Mexico, their country of origin.

(Copyright 2011 by The Associated Press.  All Rights Reserved.)