China's ocean authority Wednesday ordered ConocoPhillips China (COPC) to immediately suspend operations at two platforms in the Penglai oilfield in the Bohai Bay following two spills, saying that risks of new leaks still exist.

The measures, mainly temporary and remedial, that COPC had taken failed to eliminate risks of new leaks entirely, after oil leaks were first detected early last month in platforms B and C of Penglai 19-3 oilfield, the State Oceanic Administration (SOA) said in a statement.

The situation concerning the oil leaks in Penglai 19-3 oilfield, which is being operated by COPC under an arrangement with China's largest offshore oil producer CNOOC, had not been brought under full control by COPC yet, the administration said.

Monitoring conducted recently through remote sensing satellites and inspectors' visits found that oil had continued to spill for days from around the oilfield's platforms B and C, the SOA said.

Investigations found that there were still oil belts around the two platforms as well as signs indicating that oil leaks may happen again around platform B, the administration added.

COPC was responsible for the leaks, which seriously polluted 840 km of sea area in the Bohai Bay, sending water quality ratings in the area to their lowest level, the SOA has said.

Earlier, the leaks at the platforms B and C in Penglai 19-3 oilfield had reportedly been brought under control by COPC on June 19 and 21, respectively.