The Panama-registered oil tanker Sanchi sank in the East China Sea on Sunday afternoon, eight days after colliding with another cargo vessel, as a subsequent oil slick continues to blaze, the Ministry of Transport said.

The ship sank at 4:45 pm, 151 nautical miles from the collision site, the ministry said.

According to China Central Television, the oil slick and wreck continues to blaze on the surface of the water, forming a 10 square kilometer oil contamination belt.

The Sanchi, carrying 136,000 metric tons of highly flammable condensate oil, or natural gasoline, collided with a Hong Kong-registered cargo ship around 8 pm on Jan 6, about 160 nautical miles east of Shanghai.

The ship caught fire after the collision. There was a blast on Sunday at noon, which caused the front of the ship to collapse. The ship tilted, withflames reaching 800 to 1,000meters high, the transport ministry said.

As of 1:45 pm on Sunday, the Sanchi was obscured by thick smoke and it was not possible to see the shape of the ship.

After the collision, the Sanchi's 32 crew members - 30 Iranians and two Bangladeshis- were missing and the cargo ship's 21 crew members were rescued.

As of Sunday, a week after the collision, three bodies had been recovered. Two were found by the salvage team Saturday on the Sanchiand one was discovered at the collision site on Jan 8.

On Saturday, Chinese Foreign Minister Wang Yi told his Iranian counterpart, Mohammad Javad Zarif, over the phone that "China will continue to carry out 100 percent effort as long as 1 percent of hope remains".

Zarif expressed gratitude for China's efforts to rescue the Iranian sailors, and said Iran is willing to keep close communication and cooperation with China on the matter.

On Saturday morning, four rescuers were placed on the back of the Sanchi by a crane. They found two bodies The ship's "black box" had also been retrieved, according to a release from the Ministry of Transport.

Rescuers also entered the ship's bridge but no bodies were found. The rescue team tried to enter the living area, but the temperature hit 89 degrees and they were not able to enter.

As the wind changed direction and made it too dangerous for rescuers to remain in the toxic smoke, the rescue mission ended in half an hour and the rescue team left the ship, the release said.

Thirteen vessels - 10 Chinese, two Japanese and one from South Korea - are participating in the search and rescue operation, including searching for victims, contamination control and putting out the fire.

The consistency of petroleum material in the seawater in the nearby area has been up to 25 micrograms per liter, according to an analysis from the State Oceanic Administration on Saturday.

The oil spill was discovered since last week, and whether the sunken ship will cause worse contamination awaits further monitoring, it said.

Zhang Yong, an engineer from the administration, told CCTV that the condensate, a type of ultra-light oil, has a comparatively less damaging effect than other crude oil because of its high volatility.

"We conducted experiments in the lab, in which 90 percent of the oil will evaporate into the air in an hour. We did not do experiments in the sea but it is estimated to volatilize in a dozen minutes. Ninety-nine percent will enter the air," he said.