The cargo ship, whose origin is unknown, is now anchored off the port of Busan on the country's southeast coast. It was not immediately known what the violations were, Yonhap news agency reported.

In late March, another 3,000-ton cargo ship, the DEYI, which was headed to Vladivostok, Russia, was seized in waters off Yeosu along the southern coast under similar suspicions.

The ship is also currently docked at the port of Busan, with the captain and other crew on board.