China's maritime authority said Tuesday it will sue the American company behind a massive oil spill off its northeast coast for "damage to the environment". US oil giant ConocoPhillips has said 2,100 barrels of oil leaked from the platform it operates with a Chinese partner in Bohai Bay. The State Oceanic Administration website said it planned to sue ConocoPhillips after the spill reportedly polluted beaches and killed marine life in the area. "In June 2011, ConocoPhillips (China)'s development of the Penglai 19-3 oilfield caused a spill that caused damage to the environment," the SOA's North China Sea branch said. "The SOA will, on behalf of the country, file lawsuits against companies responsible for the leaks." The SOA made no mention of the China National Offshore Oil Corporation (CNOOC), the Chinese state-owned company that is a majority partner in the Bohai drilling operation. "The amount in damages has yet to be determined," SOA spokeswoman Shen Jiaohong told AFP, dismissing a report that said it would demand 100 million yuan ($15.6 million). Earlier reports indicated that the maximum fine for maritime pollution under China's current law is 200,000 yuan ($31,000). Both companies have apologised for the spill, and ConocoPhillips said last week it hoped to clean up the oil by the end of August. No one at ConocoPhillips (China) was immediately available for comment. 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.