Tokyo, Japan (CNN) -- Two cargo ships collided just outside Tokyo Bay, according to the Japanese Coast Guard.
The Panamanian-flagged Beagle III crashed into another vessel, the South Korean-registered Pegasus Prime, causing it to sink. The incident occurred southeast of the Miura Peninsula in Kanagawa Prefecture.
Of the 20 crew members -- all of whom are Chinese nationals -- aboard Beagle III, 12 have been found and eight are still missing.
Of the rescued crew members, six have slight injuries. The Chief Engineer of he ship was found drifting and seriously injured on Tuesday, He was taken to the nearby Miura City Hospital in a "state of cardiopulmonary arrest," but was confirmed dead Tuesday, the Japan Coast Guard confirmed.
The 14 crew aboard the other vessel, Pegasus Prime, are all accounted for, according to the Coast Guard.
The two ships collided at 3:20 a.m. Tuesday.
Japan's Transportation Safety Board has dispatched five marine accident investigators to look into the cause of the accident.
The area the collision occurred is the entrance of Tokyo Bay, a well-known sea route for more than 400 vessels that use the port in Tokyo or Yokohama.
Beagle III, a 12,630-ton general cargo ship, last reported its position as just south of the entrance to Tokyo Bay. It is currently reported as "out of range." Its last known port was nearby Yokohama. The Coast Guard has confirmed that it had departed Yokohama and was heading to Kobe.
The 7,406-ton Pegasus Prime had departed Kunsan, South Korea and was heading to Tokyo.
The Chinese Embassy reported that the search and rescue operation is comprised of 10 ships and a helicopter. The statement also indicated that "emergency mechanisms" were in place between the Japanese and Chinese authorities in Tokyo to ensure proper cooperation and continued efforts to search for the remaining missing crew members.
The Japan Coast Guard is continuing search operations by patrol boats and aircraft, but there have been no clues regarding the missing crew members yet, they said Wednesday.
CNN's Junko Ogura reported in Tokyo and Euan McKirdy wrote in Hong Kong.