It is the latest move the country has taken to strengthen supervision of the South China Sea.

On Tuesday, the State Council approved a marine zoning plan for the southern provinces of Guangdong and Hainan before 2020, emphasizing offshore law enforcement capacity in both plans.

President Hu Jintao emphasized that the country's maritime interests should be strongly protected, as he opened the 18th National Congress of the Communist Party of China on Thursday.

China is preparing itself to deal with complicated marine disputes.

On July 24, Sansha city, Hainan province, the country's newest city, was established on Yongxing Island to administer the Xisha, Zhongsha and Nansha islands and their surrounding waters.

Another 36 inspection ships are expected to join the China Marine Surveillance fleet by 2013.

An insider told China Daily that a high-level maritime interests protection office was established recently with heads of the related ministries or administrations on board.

The maritime safety administrations of three provinces and one autonomous region - Guangxi, Guangdong, Fujian and Hainan - launch their first joint patrol in the South China Sea on Wednesday. Haixun 31, one of China's largest patrol ships, is part of the five-day patrol fleet. [Photo/Xinhua]