BEIJING, Jan. 14 (Xinhua) -- The oil tanker which caught fire after it collided with a freighter in the East China Sea a week ago sunk Sunday afternoon, China's maritime authority said.

The State Oceanic Administration (SOA) said in a statement that it had detected fires and dense black smoke in a large area around the Panama-registered oil tanker Sanchi at around 10 a.m. Sunday and the entire ship sunk at around 3 p.m.

A large amount of spilled oil is still burning on the surface around the site, the SOA said.

The administration said it will monitor the oil spills and evaluate the accident's impact on the marine environment.

Sanchi, carrying 136,000 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 River estuary on Jan. 6.