State-run China Central Television reported Sunday evening that the tanker was still floating and burning, and that oil was visible in the water.
Some 30 Iranians and two Bangladeshis who were working on the oil tanker are missing.
An Iranian oil tanker collided with a bulk freighter and caught fire off China's east coast, leaving the tanker's entire crew of 32 missing and causing it to spill oil into the sea, authorities said today.
The Chinese vessel had been damaged but "the safety of the ship was not jeopardized" and all its 21 Chinese crew had been rescued, officials from the Ministry of Transport said.
The incident occurred late on Saturday about 160 nautical miles off the coast near Shanghai and the mouth of the Yangtze River Delta.More news: Halep, Siniakova set up Shenzhen final
The Chinese vessel, carrying grain from the U.S., suffered minor damage "without jeopardising the safety of the ship".
Reuters reports that the Panama-flagged Sanchi is managed by the National Iranian Tanker Company (NITC), owned by Bright Shipping and chartered by Hanwha Total Petrochemical.
Chinese authorities have dispatched eight ships for the search and rescue operation, while South Korea have sent a plane and coastguard ship to help. "There is an oil slick and we are pushing forward with rescue efforts".
South Korea has also sent a coast guard ship and a helicopter to aid the relief effort.