China's patrol ship "Haijian 83" is seen in waters of South China Sea. The patrol by China Marine Surveillance, the country's maritime law enforcement authorities, was carried out by two patrol ships "Haijian 83" and "Haijian 75", which arrived in waters near the Zengmu Reef and the offshore oil and gas fields of South China Sea from March 5 to 20, 2012. (Xinhua/Rong Shoujun)