South Korea conducted a regular military exercise last week for the defense of a disputed pair of islets it controls in the Sea of Japan, Yonhap News Agency reported Wednesday.

The Defense Ministry has withheld information regarding the reported drills, apparently to avoid heightening tensions with Japan, which regards the islets as part of its territory and calls them Takeshima. South Korea calls the outcroppings Dokdo.

Citing multiple sources, the Yonhap report said the exercise did not include any landing and was instead conducted in waters near the islets. It reportedly involved the navy, maritime police and the air force.

Footage taken in August 2021 from the South Korean government's livestream video shows a pair of islets called Takeshima in Japan and Dokdo in South Korea. (Kyodo)

The ministry declined Wednesday to confirm information about the drills.

In the wake of the report, Japan lodged a strong protest with South Korea through diplomatic channels both in Tokyo and Seoul.

Takehiro Funakoshi, director general of the Japanese Foreign Ministry's Asian and Oceanian Affairs Bureau, told Kim Yong Gil, a minister at the South Korean Embassy in Tokyo, that Japan can never accept the drills and finds them "extremely regrettable," according to the Japanese ministry.

Funakoshi was quoted by the ministry as saying the islets are an inherent part of Japanese territory in light of historical facts and based on international law.

The islets are a constant source of dispute between the two countries. In November, the chief of the South Korean police visited Takeshima in the first such landing by a serving police chief in about 12 years, prompting protests from the Japanese government.

South Korea holds regular drills around the islets twice a year. An earlier exercise was held in June.

The country has stationed security personnel there since 1954.

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