SEOUL -- South Korea on Sunday protested Japan's repeated territorial claims to the islets lying halfway between the two countries, called Dokdo by South Korea and Takeshima by Japan.

The Ministry of Foreign Affairs said in a statement that regarding the so-called "Takeshima Day" event hosted by Japan's Shimane Prefecture, the South Korean government strongly protested against Japan's repeated and unjust territorial claims over Dokdo.

The prefecture has held annual events to claim its administrative sovereignty over the rocky islets since it designated Feb 22 as Takeshima Day in 2005.

The ministry sternly urged Japan to immediately abolish the event, stressing that Dokdo is clearly an integral part of the South Korean territory historically, geographically and under international law.

The ministry added that the Japanese government should immediately stop its unjust and groundless claims to Dokdo and squarely face history with a humble attitude.

South Korea restored its sovereignty over the islets following the Korean Peninsula's liberation from the 1910-1945 Japanese colonial rule. Seoul has since been in effective control of Dokdo, with a small police detachment deployed.

South Koreans see Japan's territorial claims to the islets as a denial of the colonial history.