Lawmakers from major parties visited Korea’s easternmost Dokdo Islets on Monday to mark the 71st anniversary of the nation’s liberation from Japanese rule (1910-1945).

Ten lawmakers landed on the Dokdo Islets by helicopter at around 8 a.m. for a tour. They met with the coast guard stationed there as well as civic groups.

It was the first such trip by Korean lawmakers since 2013 when a group of politicians visited the Dokdo Islets to counter Japan’s territorial claims to it.

“(The visit) is a part of the routine job as a member of the National Assembly,” said Rep. Na Kyung-won of the ruling Saenuri Party, who led the bipartisan delegates. The group also included two members from the main opposition The Minjoo Party of Korea and one from the People’s Party.

Citing Tokyo’s protest of the visit, the former chairwoman of the Foreign Affairs and Unification Committee denounced Japan for “overreacting” to the lawmakers’ visit to their own territory, dismissing the neighbor state’s argument as something that “is beyond comprehension and common sense.”

Japan has made repeated claims to the islets, most recently on Aug. 2 when it referred to the Dokdo Islets as its territory in a defense white paper.

Following the visit, the Japanese government lodged a protest.

“It is extremely regrettable that this visit took place despite protests beforehand,” Japan’s Chief Cabinet Secretary Yoshihide Suga told a news conference Monday.

Since the lawmakers’ trip plan was released over the weekend, Japan’s Foreign Ministry officials have delivered complaints. Korea’s Foreign Ministry officials refused to accept the complaints, according to diplomatic sources.

Although rare, South Korean politicians have made visits to the Dokdo Islets in the past. The most recent visit was by former chairman of the Minjoo Party Moon Jae-in, who made a trip there last month.

Another high-profile visit was by former President Lee Myung-bak in 2012.

Japan had reacted to the presidential visit by temporarily calling in its ambassador to Korea and pushing to take the case to the International Court of Justice.

It has been a long-held position of the Seoul government that Tokyo’s incessant public claims over the islets and open protests are aimed at depicting the issue as an international conflict. The South Korean government maintains that the sovereignty of the Dokdo Islets controlled by Korea has no room for dispute.

Some experts warned that the move is not helpful and that the islets should not be used to boost a politician’s political profile.

“I doubt that there was diplomatic consideration before pushing for the visit,” said Hosaka Yuji, a professor who studies Japan and regional politics at Sejong University, told The Korea Herald. The Japanese-turned-Korean scholar is a prominent advocate of Seoul’s claim to the islets.

“The Dokdo (Islets) issue requires delicate strategy. Politicians should refrain from acting emotionally and being obsessed with domestic politics.”

By Yeo Jun-suk(jasonyeo@heraldcorp.com)