Two former Chinese military servicemen have been arrested in South Korea in separate cases of apparent espionage, involving alleged attempts to surveil South Korean military operations and US forces stationed in the country, police said.

In one case, a man is accused of intercepting flight communications near an airbase where US fighter jets are based, while in the other, information about military drills between US and South Korean forces was allegedly obtained.

South Korea is a key ally of the US in Asia, and hosts its largest overseas military installation.

Both men have been charged with aiding an enemy state. In response to CNN’s request for comment, China’s Foreign Ministry said it was “not familiar with the situation.”

Military drills information

In 2022, a Korean-Chinese man in his 40s allegedly developed a personal relationship with a Korean woman who worked at Camp Humphreys – located in Pyeongtaek about 40 miles south of Seoul.

The base is home to US Forces Korea and other major commands, making it a key center for US military operations and readiness on the Korean Peninsula.

Korean media reports say the man gave the woman money for military information about the base.

The Gyeonggi Nambu police national security investigation division said the man obtained information about US-South Korea joint military exercises, including Ulchi Freedom Shield, as well as changes in command positions, police said.

Ulchi Freedom Shield is an annual joint military exercise conducted by the United States and South Korea to strengthen their combined defense capabilities and readiness. Authorities have informed the US military about the case. This year’s Ulchi Freedom Shield drills are due to start next week.

Police said the man was a former Chinese military serviceman who had operated a military supply store near Camp Humphreys since 2021. He told police he needed the information for his military equipment business, according to investigators.

The man was charged Monday with aiding an enemy state and violating the Military Base and Installations Protection Act.

The woman involved had been removed from her position by the time investigations began.

Separate airport communications case

The second case involves a Chinese man in his 60s who police said also previously served in the Chinese military.

He was arrested on Monday on charges of aiding an enemy state and violating the Communications Secrets Protection Act after allegedly using a software-defined radio, or SDR, to intercept communications near Gunsan Airport in North Jeolla Province, about 110 miles (180 kilometers) south of Seoul.

Gunsan Airport is a joint military and civilian airport near Kunsan Air Base, which is home to the US Air Force’s 8th Fighter Wing.

Police allege the man entered South Korea on a tourist visa several times from January 2024 and stayed about a week for each trip.

He’s accused of checking into a hotel near the airport and using a small SDR to intercept military communications.

During questioning, police said the man told investigators that “listening to military-related communications is my hobby.” Officers are analyzing the content of the intercepted communications to determine whether the information was sent to China.

South Korea’s Defense Ministry and the United States Forces Korea declined to comment. (CNN)