The tanker's 32 crew members including 30 Iranians and two Bangladeshi sailors were missing in the incident.
An Iranian oil tanker carrying gas condensate collided with a Chinese cargo ship and exploded in the eastern coasts of China, Kasra Nouri, spokesman for the Iranian oil ministry, said January 7.
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.
The ministry said all 21 Chinese crew members were rescued from the damaged cargo vessel. He said the tanker was on its way to South Korea.
The Sanchi tanker run by Iran's top oil shipping operator, collided with the CF Crystal about 160 nautical miles off China's coast near Shanghai and the mouth of the Yangtze River Delta on Saturday evening.
By comparison, the Exxon Valdez was carrying 1.26 million barrels of crude oil when it spilled 260,000 barrels into Prince William Sound off Alaska in 1989. The size of the oil slick caused by the accident also was not known.
Four rescue ships and three cleaning boats had been sent to the site by 9 am local time on Sunday, the ministry added.
Eight Chinese ships and a coast guard vessel from South Korea have been sent for the search and rescue operation, Xinhua news agency said.
The 274-meter-long tanker was still ablaze on Sunday and images on Chinese television showed huge clouds of smoke rising from the stricken vessel.
The last major oil tanker disaster was the sinking of the Prestige off Spain in November 2002, which was carrying 77,000 tonnes of heavy fuel oil and caused one of Europe's worst environmental catastrophes.