Beijing (AsiaNews/Agencies) - China says that "top commanders do not have plans to increase the military presence in the South China Sea," and that it considers closed the recent diplomatic incident with a United States ship. But meanwhile, its former warship Yuzheng 311 (in the photo) is patrolling the contested Spratly and Paracel islands, and the official media are announcing the sending of six more ships to the area "to curb growing illegal fishing activity."

The announcement came on March 20 in the China Daily, which cites unspecified cabinet sources. The Spratly Islands are contested by China, the Philippines, Malaysia, Vietnam, Taiwan, and Brunei. The Paracel Islands are occupied by China, but are also claimed by Vietnam and Taiwan. The Yuzheng 311 is a 3,000-ton former warship. The source says that the patrol ships will also have helicopters on board, for efficient sea supervision.

The initiative has created growing tension with the Philippines, whose parliament on March 10 approved a law that claims the Spratly Islands as its territory (in China, they are known as the Huangyan and Nansha islands).

The defense secretary of the Philippines has commented that the sending of the Chinese ship is not "a big threat." Philippines' Navy spokesman Colonel Edgardo Arevalo maintains that "sending patrol boats by different claimant nations into the areas that they claim is tolerated," leaving open the possibility of the presence of ships from other countries.

Meanwhile, on March 7 the U.S. ship Impeccable was surrounded and threatened by five Chinese boats 120 kilometers southeast of Hainan Island. The United States lodged a formal diplomatic protest, observing that the ship was operating in international waters and was unarmed. Beijing responded that the ship was in the Chinese economic zone without authorization.

Experts observe that the South China Sea is essential for the interests of both China and the other countries in the region. A great deal of commercial traffic passes through it, and more than half of the oil in the world, some of it on its way to Japan, one of Washington's main allies. Moreover, trade relations are increasing between the United States and its former enemy Vietnam, which has claims on the Spratly and Paracel islands, believing them to be rich in gas and oil deposits. The area is rich in energy and has large populations of fish, and could see extensive tourism development. The United States is helping Hanoi to expand its own fleet.

For this reason, China wants to exclude U.S. ships from its main commercial area. But the United States is acting in accord with the UN Convention on the Law of the Sea.

It is an open secret that the ship Impeccable is capable of collecting information on underwater movement, through a gigantic submarine radar. Beijing has built a submarine base near Hainan Island.