China National Offshore Oil Corp. said 29 fishermen had sued the country’s biggest offshore energy explorer for 234 million yuan ($34 million) for economic losses following oil leaks in Bohai Bay last year.

The state-controlled parent of Cnooc Ltd. has received notification from Tianjin Maritime Court that the fishermen are seeking compensation from the company and ConocoPhillips, owners of Penglai 19-3 field, China National Offshore said in a statement on its website today.

The leaks at China’s largest offshore oilfield tainted about 870 square kilometers (336 square miles) of Bohai Bay, prompting the State Oceanic Administration to shut the field Sept. 2. The Tianjin court accepted a complaint from fishermen alleging the spilled oil killed their clams and sea cucumbers, the official Xinhua News Agency reported Dec. 30.

China National Offshore has submitted an application to the Ministry of Civil Affairs to start a maritime environmental protection fund, the company said Dec. 30. The fund won’t be used to compensate economic losses to fishermen, it said. The field, operated by ConocoPhillips, is 51 percent owned by Cnooc.