A fleet of China's marine surveillance ships has departed from China's Sanya Port to carry out regular patrol missions in the South China Sea.

Marine patrol ship "Haixun 31" sails out of the port of Sanya, south China's Hainan Province, Feb. 28, 2013. [Xinhua]

It's the second patrol mission following that of two ships which headed from Guangzhou on February 20th. The Hainan Maritime Safety Administration says the fleet consists of the Haixun 21, Haixun 31 and Haixun 166. They journeyed from South China's Hainan Province, and will voyage through waters of Sansha city, tour the Xisha, Zhongsha and Nansha Islands.

The total voyage will exceed 2,000 nautical miles and takes about half a month. The patrol is aimed at strengthening China's maritime law enforcement capacity, and testing the patrol team's rapid response abilities.

Wu Jiansheng with Guangdong Maritime Safety Administration said, "Our main task is inspecting merchant ships' acquired route, maritime traffic safety and environment, including preventing and remedying pollution, protecting the marine environment. We also provide maritime safety services, to build harmony, and provide security for freedom of navigation in South China Sea.