Beijing said it will maintain communication with the International Maritime Organization and keep it updated on managing the aftermath of the ship collision in the East China Sea.

Foreign Ministry spokesman Lu Kang made the remarks on Thursday, after Kitack Lim, the organization's secretary-general, commended those involved in efforts to rescue the crew and put out the fire.

"Following confirmation that the oil tanker Sanchi has now sunk, after the collision off the coast of China, our thoughts and hopes remain with the seafarers still missing. Our deepest condolences go to the families and loved ones of those who have lost their lives," Lim said in a recent message.

"I would like to commend all those involved in the international search and rescue operations and the efforts to battle the fire and contain pollution from the ship," Lim said, adding that efforts to contain pollution will continue, and findings of the investigation into the accident will be brought to the IMO.

The Panama-registered ship, owned by an Iranian company, collided with a Hong Kong-registered cargo ship about 160 nautical miles east of Shanghai on Jan 6. It was carrying about 136,000 tons of condensate oil and was on its way to the Republic of Korea.

On Sunday, Sanchi exploded and sank after burning for more than a week. Of the 32 crew members, three bodies have been found while the others remain missing.

Oil from the Sanchi has leaked into the sea and caused slicks.

As many as 12 ships are still carrying out emergency response operations at the site, the Ministry of Transport said on Thursday, adding that work including oil leak cleansing will continue.

Ships monitoring the site have found slicks several times, and satellite images showed they covered 101 square kilometers, the State Oceanic Administration said in its latest update.

China coordinated ships from the ROK and Japan to participate in the efforts, Lu said earlier this week.

Chinese rescuers had approached the burning ship multiple times to search for survivors and put out the fire despite danger, Lu said, adding that they boarded the ship and retrieved two bodies and the black box before it exploded.

Zhou Jin contributed to this story.