A group of four unidentified North Koreans crossed the inter-Korean maritime border in the East Sea on Tuesday, government sources confirmed to The Korea Herald.

The South Korean military, in cooperation with the Coast Guard, has secured the four North Koreans in the waters off the city of Sokcho, Gangwon Province.

The four North Koreans traveled across the border on a boat and were discovered by South Korea's Coast Guard.

The four North Koreans were transferred to a Korean vessel, which was en route to a harbor in Sokcho, Gangwon Province, as of 9:30 a.m., according to a military source.