The 32 crew-members were on board the Sanchi - a Panama-registered vessel carrying 136,000 tons of oil - which caught fire after the collision 160 nautical miles (296 km) off the coast.
An operation was underway to rescue the crew members, believed to be 30 Iranians and two Bangladeshis, according to the Xinhua news agency.
The 274-meter-long oil tanker SANCHI, owned by an Iranian shipping company, was heading to South Korea with its cargo. That is equivalent to just under one million barrels, worth about US$60 million (RM239.6), based on global crude oil prices.
Dramatic pictures show plumes of black smoke rising from the scene as the ship is engulfed by a huge fire.
It had sent four rescue ships and three cleaning boats to the site by 9am (0100 GMT) on Sunday, it added. CF Crystal's 21 Chinese crew members were rescued and the ship suffered "non-critical" damage, the ministry reports.
Oil tanker SANCHI, owned by an Iranian shipping company, collided with a cargo ship.
That was nearly twice the size of the Exxon Valdez spill, which ravaged Alaska's coast in 1989.More news: Sears - Kmart to slam the doors on 103 stores
This is the first major accident involving an Iranian oil tanker since worldwide sanctions were lifted in January 2016.
The Sanchi has operated under five different names since it was built in 2008, according the United Nations -run International Maritime Organization.
The Iranian oil tanker Sanchi burns after its collision with a freighter off China's east coast.
Norwegian ship insurer Skuld confirmed it was the lead hull insurer for the tanker and the protection and indemnity (P&I) insurer for CF Crystal.
The second vessel was Hong Kong-flagged cargo ship carrying 64,000 tonnes of grain, AFP reported.
CF Crystal, which was built in 2011, was due to arrive in China on January 10, according to Reuters ship tracking data.