A?small amount of oil continues to leak from the Penglai 19-3 field in Bohai Bay, according to satellite images from Sunday that appear to show a fresh belt of oil in the area, the State Oceanic Administration announced on Monday.

A small spill was found at Platform C and there are also signs that a spill could occur near Platform B, according to a report by the administration after a Sunday on-site inspection, reported by Shanghai Daily.

A joint supervision team from the SOA and China Marine Surveillance is on site and has asked ConocoPhillips China, the operator of the oilfield, to explain why oil still appears to be leaking.

The company has been asked to find out what is going on as soon as possible and release the information to the public, according to a notice on the SOA's website on Monday.

The team criticized ConocoPhillips for its slow action in finding out what had caused the leak and asked the company to examine all areas that might have been affected by the oil leak and block all spill sources.

ConocoPhillips China?hasn't offer any comment so far.

The 19-3 field, owned by China's CNOOC Ltd and US-based ConocoPhillips, is China's largest offshore oilfield, which?suffered two oil leaks last month at the two platforms.

ConocoPhillips holds a 49-percent stake in the project while China National Offshore Oil Corporation (CNOOC) holds the rest.

On July 5, the SOA held the first formal news conference about the spills. The SOA said the first leak, which was detected from Platform B, occurred on the seabed and resulted from increased pressure when water was injected into the well. A second incident at Platform C was said to have been due to a surge in the well.

As of July 4, the oil spills had polluted an area of more than 840 square kilometers in Bohai Bay, degrading the water quality from Level 1 to Level 4, which means it became about as clean as wastewater from a sewage out-flow, according to the SOA's statistics.

Dead seaweed and fish were found in the area recently.

Recent oil samples taken from Changdao, Daheishan and Daqin islands in Shandong province were not the same type of oil as the one that spilled in the recent incidents, said a notice released on the SOA's website on Saturday.

The reason for the death of the fish remains unclear because the amount of petroleum found in their bodies was within safety standards, according to the notice.