One body has been recovered but 31 crew remain missing as an explosion and high winds, rain and rough seas hamper firefighting and recovery efforts on the distressed Iranian-owned tanker burning in the East China Sea for several days.
China's Ministry of Transport said vessels attending Sanchi, which collided with a bulk carrier on Saturday night, withdrew after an explosion on the tanker's bow.
Previous statements from the transport ministry said the toxicity of the gas generated by the burning of ultra-light crude oil condensate had also hampered rescue workers, who were forced to wear biohazard protective suits and masks and use gas testing equipment.
It said 14 vessels, including numerous Chinese vessels, a South Korean coast guard vessel, fixed-wing aircraft and the US Navy, had been helping.
The owner of the 164,000DWT Sanchi, the National Iranian Tanker Company, reportedly said on Tuesday some of the missing crew members could still be alive in the tanker's engineroom, which is 14 metres below the waterline and “is not directly affected by the fire”.
Sanchi is carrying 136,000 tonnes of condensate ultra-light crude - the equivalent of a million barrels of oil.
CF Crystal, which was carrying 64,000 tonnes of grain from the United States to Guangdong, China, sustained significant damage to its bow in the collision.
In other developments, Iran has requested assistance from the Japan Coast Guard in the rescue-and-recovery operations for Sanchi, and Iran’s Ports and Maritime Organisation and National Iranian Tanker Company will begin a joint investigation into the tanker disaster.
BBC reports no large oil spill has been detected. Experts at the scene reportedly believed no more than one per cent of the condensate was on the surface of the water, the ministry said.
The Washington Post reports the stricken ship had drifted 65 nautical miles south east from the site of the collision at the mouth of the Yangtze River Delta by Wednesday evening.