The government is urging North Korea to return a South Korean fishing boat that drifted into North Korean waters on Thursday.

The government conveyed the message shortly after the 29-ton “800 Yeonan-ho” was towed to the communist state after it crossed over the Northern Limit Line in the East Sea.

During an exchange of messages on Thursday afternoon, North Korean authorities said the ship’s crew of four was under investigation by related agencies.

The North added that it would keep Seoul updated on any developments.

The government believes the North will return the crew of the Yeonan soon, just as it did when other South Korean vessels ventured into North Korean waters in 2005 and in 2006. However, there are concerns that strained inter-Korean relations could play a part in settling the issue.

Meanwhile, South Korea’s Joint Chiefs of Staff said a North Korean fishing vessel that crossed into South Korean waters around 5:10 p.m. on Thursday was led back into North Korean territory as part of efforts not to further mount tensions between the two nations.