South Korea has rejected Japan's renewed protest against Seoul conducting a marine survey in waters off the Dokdo islets in the East Sea. 

Japan’s foreign ministry said that a South Korean research vessel carried out a marine survey again on Tuesday, about a week after the previous survey, intruding into what it claims to be the Exclusive Economic Zone around Takeshima, the Japanese name for the Dokdo islets.

The head of the ministry's Asian and Oceanian Affairs Bureau, Namazu Hiroyuki, communicated Japan’s opposition to the research activity to a senior diplomat from the South Korean Embassy in Tokyo, calling for an immediate halt. A similar protest was lodged by the Japanese Embassy in Seoul with the South Korean foreign ministry.

An official from the South Korean foreign ministry dismissed the protest, saying that Dokdo is South Korea's own territory historically, geographically and by international law and that no sovereignty claims to Dokdo by Japan can be accepted. 

The official added that the government rejected Japan’s protest against the research activity, adding Seoul plans to firmly respond to Japan’s unjust claims to South Korea’s Dokdo islets.