China is strengthening its maritime surveillance capacities to deal with the complicated sea disputes and safeguard the country's maritime rights, a senior official said on Sunday.

Two Chinese surveillance ship fleets have arrived at waters around Diaoyu Islands and its affiliated islets Friday morning and started patrol and law enforcement there.

The China Marine Surveillance fleet will enhance patrols off the important islands to demonstrate the country's sovereignty, Xiao Huiwu, deputy director of CMS told China Daily.

"CMS will stop all the illegal activities in the country's territorial waters, guaranteeing China's maritime rights," Xiao said.

On Sept 14, six Chinese surveillance ships patrolled the waters around China's Diaoyu Islands after Beijing announced the exact longitude and latitude of Diaoyu Island and 70 of its affiliated islets and published location and topographical maps and sketches of the island on Sept 15.

During the patrol, illegal ships and planes were detected and CMS officers demanded they leave, demonstrating the country's jurisdiction over the islands and their affiliated waters, Xiao said.

It is one of the series of actions taken by China after Tokyo announced its intention to "purchase" and "nationalize" the Diaoyu Islands.

Xiao said CMS is responsible for enforcing laws and order within China's territorial waters, exclusive economic zones and shores, protecting the maritime environment and natural resources and carrying out maritime surveys.

"It is our duty to protect the country's maritime interests," he said, adding that the daily law enforcement work conducted by CMS is based on the law on island protection, the law on territorial sea and the contiguous zone and other laws.

On Sept 12, the State Oceanic Administration released on its website a new regulation to protect territorial waters, "providing legal support to the CMS in law enforcement during offshore patrols", Lu Caixia, director of the islands management department at the agency said.

CMS deploys nine patrol vessels and three planes to monitor China's waters day and night, he added.

According to the latest statistics from CMS, it has more than 200 ships, including 28 ships with tonnage of more than 1,000, and nine planes and about 10,000 people are working in CMS to monitor marine affairs.

As of June, the patrol fleet in the East China Sea monitored 513 foreign ships and 529 foreign planes in 2012, protecting the country's maritime rights and interests, the figures showed.

CMS said earlier this year that another 36 inspection ships are expected to join the surveillance fleet by 2013, including seven vessels with tonnage of 1,500, 15 with tonnage of 1,000, and the rest with tonnage of 600, which will be distributed across 14 provinces and regions along the country's coastline.

Xiao said the maritime disputes between China and other countries will be more complicated and CMS will take the necessary responsibilities to protect the country's maritime rights.

Relations between China and the Philippines have been strained because the Philippine government launched a provocative move to unilaterally rename the Luzon Sea and waters within, around and adjacent to China's Nansha Islands and Huangyan Island as the "West Philippine Sea".

Since April, tensions between China and Japan have been escalating over the Diaoyu Islands in the East China Sea.