The Dokdo Research Institute on Tuesday filed a defamation suit against the three Japanese men who placed poles with slogans claiming the Dokdo islets as Japanese territory

The three men placed the poles outside the Northeast Asian History Foundation and the Korean Council for the Women Drafted for Military Sexual Slavery by Japan in Seoul last month.

The police said that it will locate and issue summons for the suspects.

The rightwing activists Nobuyuki Suzuki, who was responsible for placing a similar pole next to the statue of a Korean girl forced into wartime sex slavery by Japan outside the Japanese Embassy in Seoul in June, has claimed to have organized last month’s act.

The development comes as Japan’s false claims the islets have escalated into to a publicity war between the two countries.

Since Sept. 11, the Japanese government has been sponsoring advertisements criticizing Korea’s “illegal occupation” of Dokdo in Japanese newspapers.

The Tokyo government is also reported to have engaged its diplomatic missions in publicizing the false claim that the Dokdo islets are Japanese territory in other nations.

Among various nations, Japan is thought to be focusing much of its related efforts on the U.S.

As Japan takes increasingly stronger measures to publicize its claims over Dokdo on the international stage, the Seoul government has sent out response guidelines to its diplomatic missions and is reviewing plans to launch a publicity campaign of its own.

The ministry is also reviewing plans to take out advertisements in Japanese media, and employing social networking services and popular culture to promote Seoul’s cause.

Measures under review include employing the services of the singer Psy of “Gangnam Style” to produce “Dokdo Style.”

The Korean Foreign Ministry also requested 4.2 billion won ($3.8 million) for its Dokdo publicity efforts in 2013, an increase of 81 percent from this year.

By Choi He-suk  (cheesuk@heraldcorp.com)