The joint inspection by six government departments came after an oil spill at a platform in north China's Bohai Bay caused the country's worst offshore pollution in June this year.

The three-week inspection will be conducted by the Ministry of Land and Resources, the Ministry of Environmental Protection, the Ministry of Agriculture, the State Administration of Work Safety, the National Energy Administration and the State Oceanic Administration from Oct 15 to Nov 4.

During the period, six inspection teams will check oil drilling and exploration platforms, pipelines, floating production storage and offloading facilities, onshore terminals, docks and transport vessels affiliated with state-owned oil giants CNPC, Sinopec and CNOOC, as well as foreign operators in the Bohai Sea, the East China Sea and the South China Sea.

Compensation procedures for environmental damage caused by oil that leaked from an oil drilling platform operated by Houston-based ConocoPhillips' China branch are under way.

The oil spills have polluted more than 5,500 square km of water in Bohai Bay since June.