BEIJING, Jan. 19 -- China made the utmost efforts in rescue work for oil tanker Sanchi, an official said.

More than 10 vessels were mobilized in the operation each day, Zhi Guanglu, an official with the Ministry of Transportation (MOT) told a press conference Friday.

"As there were no similar incidents in history, we have no rescue practice or experience to follow, posing huge difficulties for the rescue...but saving people's lives is our top priority," Zhi said.

Local rescue forces from Shandong and Zhejiang provinces worked closely with those of Japan and the Republic of Korea in searching over 8,800 square kilometers of sea, he said.

"We will continue investigations in accordance with international treaties and laws, and keep close contact with all sides," Zhi said, adding that China will invite professionals and all related parties to witness the restoration of navigation data recorder.

The Panama-registered oil tanker Sanchi, carrying 113,000 tonnes of light crude oil from Iran, collided with the CF Crystal, a Hong Kong-registered bulk freighter, about 300 kilometers east of the Yangtze estuary on Jan. 6.

Thirty-two crew of the tanker -- 30 Iranians and two Bangladeshis -- were lost.