Six South Koreans have been indicted after they allegedly bought and resold U.S. military equipment banned from circulation, police said Monday.

The group, including a man surnamed Kim, is suspected of purchasing seven U.S. military items, such as night vision goggles and laser target designators, from an unidentified soldier stationed at a U.S. military base in Dongducheon, 40 km north of Seoul, in May of last year, the Seoul Metropolitan Police Agency said.

Kim then allegedly smuggled the pieces out of the country and sold each for between 1.5 million won ($1,356) and 3 million won in Japan and Taiwan.

The night vision devices are attached to automatic machine guns and helmets to enhance visibility during night-time operations, the SMPA added.

Another suspect, identified only by his surname Hwang, is charged with buying large amounts of U.S. military equipment, such as helmets, bulletproof vests and clubs, from U.S. soldiers and selling them to civilians from his store near the base, the SMPA said.

The suspects claimed during police questioning that the U.S. soldiers first approached them about the trade, the police said.

The SMPA said they will work closely with U.S. intelligence agencies including Homeland Security Investigations and the U.S. Department of Defense to further investigate similar cases. (Yonhap News)