China's ocean watchdog on Wednesday ordered ConocoPhillips China (COPC) to immediately suspend the operation of two of its platforms in north China following the oil spills, saying that the risk of more spills still exists.

Photo taken on July 13, 2011 shows Suizhong 36-1 oilfield on Bohai Sea, offshored the northeast China's Liaoning Province. A new leak occurred in Suizhong 36-1 oilfield of China National Offshore Oil Corporation (CNOOC) at about 1:30 a.m. [Xinhua]

China's State Oceanic Administration (SOA) sharply criticized ConocoPhillips China Inc on Wednesday in a notice released on its official website for not having an effective means of preventing oil leaks.

The oil giant has had to deal with three accidents over the last week, including two other oil spills in northeast China's Bohai Bay and a fire in one of its refineries in south China's Guangdong Province.

The leaks have polluted at least 840 square kilometers of seawater in Bohai Bay, in the northern part of the Yellow Sea, and have proved to be a "great threat" to the environment there, according to the notice.

To clean up the bay and to ensure the oil found there is obtained in a safe and sustainable manner, the administration asked ConocoPhillips China to immediately suspend the operations of two platforms at the Penglai 19-3 Oilfield, the source of the leak, and eliminate the risk of fresh leaks as soon as possible, according to the notice.

A new oilfield located in Bohai Bay was discovered to be leaking oil Tuesday morning, the China National Offshore Oil Corporation (CNOOC) said.

An oil slick in the Suizhong 36-1 oilfield, located in north China's Bohai Bay, has been cleaned up and an emergency alert for the region has been lifted, according to the CNOOC, China's largest offshore oil producer.

The oil spill occurred at about 1:30 a.m. Tuesday, when the centralized control system used to operate the oilfield's central platform broke down.

ConocoPhillips China has said previously that the work to clean up the bay is almost finished, but admitted on Tuesday that "minor residual seepage" may continue and only diminish over time.

The total production from these two platforms was approximately 47,000 barrels per day, which represents a third of the production from the entire PL 19-3 field.

The company said it is currently re-evaluating all its development plans for the field to ensure that the kind of seepage does not occur again.

The Penglai 19-3 Oilfield is the largest offshore oilfield in China. ConocoPhillips China holds a 49-percent stake in the project and the China National Offshore Oil Corp holds the rest.