The fishing community and civic groups on the southernmost island of Jeju have strongly condemned Japan's planned release of radioactive water from the crippled Fukushima nuclear power plant into the ocean.

An alliance of over 50 organizations staged a rally across from the Japanese consulate general on the island on Tuesday, calling on Tokyo to immediately withdraw the water release plan.

Taking note of ongoing protests and rallies against the water release within Japan, the group urged Tokyo to call off the plan that they likened to an international crime, calling for the water to instead be stored within its borders.

The group said that despite doubts about the plan's safety spreading around the world, the South Korean government claims such concerns are based on unfounded rumors.

The rally participants, which the police estimated at some 800, delivered a letter of protest to the Japanese consulate general. They also burned a banner with a picture of the "Rising Sun" flag, regarded by South Koreans and other Asian countries as a symbol of Japan's wartime aggression and militarism in the first half of the 20th century.