SAN DIEGO (AP) — Two U.S. Navy sailors have been arrested on charges related to national security and tied to China, U.S. officials said Thursday.

A 22-year-old sailor assigned to a ship in San Diego was arrested Wednesday on a charge related to espionage involving conspiracy to send national defense information to Chinese officials, according to the U.S. officials, who were not authorized to discuss the matter publicly and spoke on condition of anonymity.

Another sailor was arrested at Naval Base Ventura County north of Los Angeles and charged with conspiracy and receipt of a bribe from a Chinese official, the U.S. officials said. It was unclear if the two cases were related.

The U.S. Justice Department declined to comment when contacted by The Associated Press. Federal officials were expected to release more details at a press conference scheduled in San Diego later Thursday.