Ghost ships with bodies on board haunt Sea of Japan

Japanese Coastguard inspect one of the abandoned vessels. Photo / Supplied

Eleven ghost ships, some with decaying corpses on board, have turned up off the coast of Japan.

The bodies of 20 as-yet-unidentified people were on the wooden boats, found in the past two months. Four ships washed up in early November and another seven were spotted floating in the Sea of Japan in the past three weeks.

Experts say the badly damaged vessels may have been at sea for months.

One of the ships, spotted by Coastguard about 100km offshore on the Sea of Japan this week, was pulled ashore at Fukui Port, about 400km north of Tokyo. The bodies of three people were found on board.

Authorities are investigating where the fleet came from but Japanese media speculated the boats may have come from North Korea, about 1000km across the Sea of Japan.

Korean writing could be seen on the boats and on clothing inside the vessels. What appears to be the remains of a North Korean flag have been found.

Tangled ropes, hooks and other fishing equipment found on the boats suggest they may be fishing craft from North Korea. A number of fishing ships from the impoverished state have been lost because many lack modern equipment such as GPS.

Others have suggested the boats were fleeing Kim Jong-un's oppressive rule and got caught in a storm.