South Korea has issued a navigational warning for ships off the east coast next week over its routine naval firing drills, officials said Friday.

The Korea Hydrographic and Oceanographic Agency issued the warning earlier this week as the Joint Chiefs of Staff announced its plan for "regular maritime firing drills" in waters south of Ulleung Island in the East Sea from Monday through Friday, according to the agency officials.

The agency said it informed Japan of the updated navigational warning on Thursday.

Ulleung Island is located northwest of South Korea's easternmost islets of Dokdo.

South Korea has been in effective control of the islets of Dokdo, with a small police detachment, since its liberation from Japanese colonial rule in 1945. Still, Japan repeatedly claims sovereignty to the rocky outcroppings.

Dokdo -- which lies closer to South Korea in the East Sea that divides the Korean Peninsula and Japan -- has long been a thorn in relations between the two countries. (Yonhap)