SADO, Japan (AP) — South Korea paid tribute to wartime Korean forced laborers at Japan’s Sado Island Gold Mines in a memorial ceremony on Monday, a day after boycotting a similar event organized by Japan, as tensions over historical atrocities continue to impact relations between the two sides.

Monday's ceremony at a former dormitory near the 16th century Sado mines, which were listed this summer as a UNESCO World Heritage site, was organized by South Korea’s Foreign Ministry and attended by nine families of Korean wartime laborers, the country’s ambassador to Japan and other officials.

Japan on Sunday held a memorial service for all workers at the Sado mines, including Koreans. It thanked them for their contributions at the mines but did not acknowledge their forced labor or issue an apology.

At the Korean-sponsored memorial on Monday, participants in dark suits observed a moment of silence and offered white chrysanthemums in honor of the South Korean laborers, along with offerings such as dried fish, sliced apple and pears.

In a short speech, South Korea's Ambassador to Japan Park Choel-hee offered his condolences to the forced laborers and their families, expressing hopes that the memorial would bring comfort to families. He said South Korea and Japan should both make efforts to ensure that the painful wartime history is remembered.

At the mines, about 1,500 Koreans were forced to labor under abusive and brutal conditions during World War II, historians say.

Sunday’s ceremony, which was supposed to further mend wounds, renewed tensions between the two sides. South Korea announced Saturday its decision to not attend the Japanese-organized ceremony, citing unspecified disagreements with Tokyo over the event.

There was speculation that the South Korean boycott was related to parliamentary vice minister Akiko Ikuina's attendance at Sunday’s ceremony.

Ikuina reportedly visited Tokyo’s controversial Yasukuni Shrine in August 2022, weeks after she was elected as a lawmaker. Japan’s neighbors view Yasukuni, which commemorates 2.5 million war dead, including war criminals, as a symbol of Japan’s past militarism.

The Sado mines were registered as a UNESCO cultural heritage site in July after Japan agreed to include an exhibit on the conditions of Korean forced laborers and to hold a memorial service annually, after repeated protests from the South Korean government.

Signs, including one at the site where South Koreans held their ceremony, have been erected indicating former sites of Korean laborers’ dormitories. A city-operated museum in the area also added a section about Korean laborers, but a private museum attached to the main UNESCO site doesn’t mention them at all.

The site of South Korea's memorial was the former Fourth Souai Dormitory, one of four dorms for Korean laborers without families. A newly erected sign there reads, “Workers from the Korean Peninsula lived here during the wartime.”

Copyright 2024 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed without permission.