The Department of Justice announced Thursday that two U.S. Navy sailors in California have been arrested on espionage charges after allegedly spying on behalf of China. The arrests mark the latest incident of U.S. service members mishandling or divulging sensitive military and national security information.

Federal law enforcement arrested Jinchao Wei, also know as Patrick Wei, Wednesday at a naval base in San Diego on charges that he transmitted classified information and documents to China for over a year about U.S. naval and defensive capabilities. Prosecutors allege that Wei, who served as a machinist’s mate on an amphibious vessel and had a security clearance, provided technical and mechanical manuals, blueprints and photos and videos showing the locations of various Navy ships to a Chinese intelligence officer in exchange for financial compensation. Wei also described the nature of weapons onboard his ship.

Also arrested was Wenheng Zhao, also known as Thomas Zhao, a sailor at a naval base in Ventura County, Calif. Zhao is accused of recording military information, photos and videos to a Chinese intelligence officer posing as a maritime economic researcher. Zhao also sent the Chinese intelligence officer classified plans for a “large-scale U.S. military exercise in the Indo-Pacific region” and diagrams and blueprints for a radar system stationed on a U.S. military base in Okinawa, Japan, according to the DOJ news release.