Three crewmen have been confirmed dead after the cargo ship they were on sank near Sado Island in Niigata, Japan, according to Maritime Executive.

The vessel sank early Thursday morning in the Sea of Japan with a total of 12 mariners onboard - nine Chinese and three South Korean.

Upon receiving a distress call from the sinking ship, a helicopter from Japan's Self-Defense Force located a lifeboat about 300 km northwest of Sado's Hajikizaki Island carrying the abandoned vessel's crewmen.

Japan's Coast Guard rescued all of the crewmembers, but three of the men unfortunately died while receiving medical treatment.

The Cambodia-registered freighter was travelling to Sokcho port in South Korea carrying marine products from Aomori in northern Japan. The name of the ship was not immediately available.(Source: Cargonews Asia)