A Chinese national has been charged with illegally flying a drone over Vandenberg Space Force Base in California, capturing images of the military installation, the U.S. Justice Department announced Wednesday.

Yinpiao Zhou, 39, was detained at San Francisco International Airport as he prepared to board a flight to China, according to authorities.

"This individual allegedly operated a drone over a restricted military site and recorded footage, an act that violates federal law," stated U.S. Attorney Martin Estrada. "Protecting the security of our military personnel and facilities is a top priority for my office."

The Chinese Foreign Ministry, when questioned about the incident, said it was "not aware of the situation," according to spokesperson Mao Ning during a press briefing on Thursday.

Detection systems at Vandenberg identified the drone in late November, flying approximately one mile (1.6 kilometers) above the base. Security personnel traced the drone to a nearby public park, where Zhou was reportedly found with the device concealed in his jacket.

Upon inspection, the drone contained aerial images of the base, which is a critical launch site for space missions, including SpaceX’s Falcon 9 rockets, and missile tests.

Zhou, a Chinese citizen and lawful permanent U.S. resident, most recently visited China in February. He appeared in a San Francisco court on Tuesday, facing charges of failing to register an aircraft not used for transportation and violating national defense airspace. He has yet to enter a plea.

The Justice Department confirmed that Zhou is being held in custody pending an appeal by prosecutors against a decision to release him on bail. He is scheduled to appear in a U.S. District Court in Los Angeles in the coming weeks.

The incident echoes a similar security breach in early 2023 when the U.S. intercepted a Chinese balloon suspected of espionage over sensitive military sites, escalating tensions between Washington and Beijing. China had claimed the balloon was a civilian airship that had strayed off course.