A Chinese lawyer is suing a state-owned energy giant and its US partner over a huge oil spill off China's northeast coast, amid public anger over the resulting pollution, state media said Wednesday.

More than 2,100 barrels of oil and oil-based mud -- a substance used as a lubricant in undersea drilling -- have leaked from two platforms in Bohai Bay jointly owned by ConocoPhillips and China's CNOOC.

Jia Fangyi filed the private lawsuit against the two companies with three courts in China, demanding they "immediately stop polluting the environment and clean up the pollution", the state-run Beijing Times newspaper said.

He also pressed the companies to set up a 10-billion-yuan ($1.6-billion) compensation fund to pay for damages caused by the pollution and restore the area's ecological system, it said.

Local fishermen have blamed the spill for the loss of much of their seasonal harvest, while environmental groups signed an open letter to ConocoPhillips calling for faster and more transparent clean-up efforts.

Meanwhile, Jia also plans to bring the State Oceanic Administration (SOA) to court for "administrative unresponsiveness" because it delayed reporting the oil spill to the public for a whole month, the report said.

It also failed to name CNOOC -- which has a majority stake in the oil project and shares profits from the crude produced -- as a liable party for the spill, the lawyer was quoted as saying.

The SOA -- which supervises and manages China's maritime area -- said Tuesday it planned to sue ConocoPhillips after the spill reportedly polluted beaches and killed marine life in the area. It made no mention of CNOOC.

It told AFP the amount in damages was yet to be determined. But earlier media reports said the maximum fine for maritime pollution under Chinese law is 200,000 yuan.

Both companies have apologised for the spill, and ConocoPhillips said last week it hoped to clean up the oil by the end of August.