A North Korean cargo vessel is passing through the waters between mainland South Korea and its southern resort island of Jeju, marking the first time for North Korean commercial ships to officially use South Korean sea routes.

The nine-thousand-ton Daedonggang-ho carrying salt and coal departed from the North's western port of Nampo earlier on Sunday.

Another cargo vessel, the 2,750-ton Hwanggeumsan-ho, is scheduled to pass through the Jeju straits on noon Tuesday.

The ships will be heading towards the North's eastern port city of Cheongjin.

The sailing of the ships comes after the South agreed to open its territorial waters for North Korean civilian vessels at inter-Korean talks on maritime cooperation earlier this month.