Eight bodies, almost completely decomposed, were found in a small wooden boat that washed up on a beach in Japan, the country's coast guard said.
The boat was found on a beach 70km north of a marina where eight men were identified last week who said they were from North Korea.
According to the police, these men were probably fishermen and arrived in Japan because their fishing boat had a problem.
The Coast Guard said investigations were under way to determine the nationality of the eight dead.
The remains of two men were found over the weekend off the west coast of Santo Island, also in the Sea of Japan. Although their identities remain unknown, they may have been North Koreans because packs of cigarettes from North Korea were found nearby as well as life jackets with Korean letters on them.
The gruesome findings come at a time when tensions over North Korea's nuclear and ballistic missile programs have escalated, with US President Donald Trump re-branding the Pyongyang regime a "supporter of terrorism" to impose more sanctions.
Experts estimate that food shortages in North Korea may be responsible for a number of maritime accidents involving North Korean vessels.
"North Korea is pushing people too hard to catch more fish to make up for the shortfalls," said Seo Yu-suk, a researcher at the North Korean Studies Institute in Seoul, explaining that small, aging boats facing shore are difficult weather is bad.