South Korea on Wednesday repatriated six North Koreans across the maritime border in the East Sea, months after they drifted into southern waters and were rescued.

The fishermen’s boats had drifted into South Korean waters, officials said. The South’s new president has been trying to improve ties with North Korea.

South Korea’s military says an unidentified North Korean man crossed the heavily fortified land border separating the two Koreas and is in custody.