China appears to be increasingly determined to strengthen its presence and control in areas of the South China Sea close to Southeast Asia that it sees as strategically and economically important.

The Philippines recently accused Chinese navy and maritime surveillance ships of intruding into a new part of the disputed Spratly Islands in May,evidently to lay claim to an uninhabited atoll.

The foreign ministry in Manila summoned the Chinese embassy's charge d'affaires to explain the ship's presence in what the Philippines says is its territory. This followed a meeting on May 27 over reports in the Chinese media about Chinese plans to move a giant oil rig into the southern part of the South China Sea next month. Meanwhile, Vietnam protested to Beijing over harassment of a vessel exploring for oil and natural gas off the coast of central Vietnam. China rejected both protests, saying that its actions were normal maritime law enforcement and surveillance activities in waters "under the jurisdiction of China."