Japanese media report a boat, presumed to be from North Korea, was found washed ashore on Japan's west coast. 

The wooden boat was reportedly discovered on the western coast of Okinoshima in Shimane Prefecture at around 9 a.m. Tuesday. Four North Koreans, presumed to be the ship's sailors, were found near the boat.  

They reportedly told Japanese police that they went adrift for around ten days due to engine failure. They are under investigation.  

Last year, around 200 North Korean fishing boats were found swept onto Japanese coasts.