A memorial event will be held Sunday on Japan’s Sado Island to honor laborers at the Sado mines, including Koreans forced to work there during the Japanese colonial period.

A committee charged with organizing the event said Wednesday that the service will take place in Sado City on the island, off Japan’s west coast. 

The event will see the attendance of officials from Japan’s local and central governments as well as civic groups. 

From South Korea, government officials and bereaved family members of forced laborers will take part. 

South Korea had consented to the designation of the mines as a UNESCO World Heritage Site on the condition that Japan take steps to inform international visitors about the full history behind it, including holding the memorial event.

The ceremony was reportedly set to take place as early as September but postponed due to elections and other events in Japan.