TOKYO >> Japanese police said Friday they are investigating eight men found on Japan’s northern coast who say they are from North Korea and washed ashore after their boat broke down.

Akita prefectural police found the men late today after receiving a call that suspicious men were standing around at the seaside in Yurihonjo town. Police said they also found a wooden boat at a nearby marina.

Police said the men were in good health and spoke Korean. They identified themselves as North Koreans who were fishing before the boat broke down and washed ashore.

The investigation underway will include the possibility of illegal fishing, Chief Cabinet Secretary Yoshihide Suga told reporters.

A week earlier, the Japanese Coast Guard rescued three North Korean men from a capsized fishing boat off Japan’s northern coast. They were transferred hours later to another North Korean vessel that was to return them home.

Japan and North Korea have no diplomatic ties and tensions are often high due to their colonial and wartime history and Pyongyang’s missile and nuclear threats.

Waters between Japan and the Korean Peninsula is known for its rich fishing ground, where poachers from North Korea and China have been spotted.

Wreckage believed to be North Korean boats regularly washes ashore in northern Japan during winter due to seasonal winds.

In 2015, a wooden boat drifted ashore in another coastal town in Akita and skeletal remains of two men were found — one inside the vessel and another one nearby. Three North Korean boats with 10 bodies inside also washed up on the Noto Peninsula.

This year, more than a dozen cases of wreckages were reported in three northern prefectures facing the Sea of Japan, according to the Coast Guard.