A skeleton-filled “ghost ship” that washed ashore on the Japanese coast may contain the remains of North Korean defectors, Japan’s Coast Guard announced Monday.

Officials say the “ghost ship,” which carried the remains of eight bodies, could be evidence of North Koreans trying to escape Kim Jong-un’s oppressive regime as the dictator tightened his grip on those fleeing North Korea this year, according to Fox News.

The latest discovery comes days after officials found the body of a suspected North Korean man and the remains of another wooden ship on Japan’s Sado Island.

The Japan Times reports that a Japanese resident saw the 22-foot-long wooden boat floating along the Sea of Japan Friday near Miyazawa Beach.

Officials who searched the vessel Sunday and Monday noted several “skeletonized” remains that were so decomposed that they could not tell if the bodies were male or female.

The 68-year-old woman who first saw the boat told Kyodo News she witnessed rescue workers using stretchers to carry the skeletal remains ashore.

It is unclear how the suspected defectors died.