CHINESE patrols, sometimes firing water cannon, are driving off foreign fishing boats in the South China Sea and arresting those who resist on a weekly basis, say Communist Party officials on Hainan Island, Reuters reports.

Party secretary Luo Baoming said patrols attempted to peacefully negotiate with vessels that initially ignored warnings to leave Chinese waters.

"First of all we would try to dissuade them, tell them to get out, this is our area, and then we negotiate and dissuade as much as possible," said Mr Luo.

"There's something like this happening if not every day then at least once a week, and the majority are dealt with by negotiating and persuasion," he said.

The Philippines and Vietnam have accused Chinese patrol vessels of firing water cannon and using aggressive means to intimidate and threaten its fishermen near disputed areas.

Mr Luo said that authorities based in Sansha city on Woody Island, which administers the mostly uninhabited Paracel islands, were regularly dealing with fishing vessels entering their waters.

Also claimed by Vietnam and Taiwan, Vietnamese fish the Paracels, despite hundreds being captured in past campaigns in what Vietnam describes as its legal and sovereign fishing grounds.

New rules issued by Hainan this year say its jurisdiction covers much of the South China Sea. The rules follow China's creation of a controversial air defence identification zone in late November above the East China Sea centred on a territorial dispute with Japan.

Ambiguity surrounding the rules - and their future enforcement - have puzzled a nervous region since they were introduced on January 1, apparently stretching into international waters.

Hainan, which juts into the South China Sea, claims two million square kilometres of the South China Sea which covers 3.5 million square kilometres.

Beijing claims almost all of the oil and gas resources of the South China Sea, rejecting rival claims to parts of it from the Philippines, Taiwan, Malaysia, Brunei and Vietnam, Reuters said.

Separately, the US Defence Department's annual Freedom of Navigation Report to Congress for the 2013 fiscal year targeted "excessive" claims about its maritime boundaries and its effort to force foreign warships to obtain permission before peacefully transiting claimed waters.

Since 1991, the United States has conducted more than 300 freedom of navigation operations challenging maritime claims by 53 different countries worldwide, from Albania, Ecuador and Denmark to Pakistan and Yemen.

Iran and the Philippines have been challenged most frequently. Iran has appeared on 19 of the 21 lists submitted to Congress since 1991, while the Philippines has appeared on 18. Cambodia, the Maldives, India and Oman also frequently appear.

China has been on the list 11 times, the same as Indonesia and one less than Burma.

The most frequent US complaint is with countries that measure the start of their territorial waters by drawing a straight line between two points on the coast or along offshore islands, thereby enclosing a vast expanse of sea.

Washington disagrees with the Philippines' designation of the seas bounded by the island chain as internal waters and therefore off limits to foreign ships or overflight by foreign aircraft.