North Korean cargo vessels are heading home with fertilizer loaded from three ports in South Korea from Sunday.

At the southwestern port of Kunsan Wednesday, the Wonsan No. 2 left for the North's port of Nampo at 4 am carrying 2,000 tons of compost fertilizer.

In Ulsan, the Mount Paektu, named after the North's highest peak, left for Wonsan at noon with 2,000 tons of urea fertilizer.

On Tuesday, the Botonggang, named for a famous North Korean river, departed Yeosu for Nampo after loading 8,000 tons of compost fertilizer overnight.

The Unification Ministry said more North Korean vessels will make 22 trips into South Korean waters to transport fertilizer.