BEIJING - Reuters:


A handout picture of Chinese marine surveillance ship, offshore of Vietnam's central Phu Yen province May 26, 2011 and released by Petrovietnam May 29, 2011. REUTERS/Handout

China's powerful Central Military Commission has approved the formal establishment of a military garrison for the disputed South China Sea, state media said on Sunday, in a move which could further boost tensions in already fractious region.

China has a substantial military presence in the South China Sea and the move is essentially a further assertion of its sovereignty claims after it last month upped the administrative status of the seas to the level of a city, which it calls Sansha.

The official Xinhua news agency said the Sansha garrison would be responsible for "national defense mobilization ... guarding the city and supporting local emergency rescue and disaster relief" and "carrying out military missions".

It provided no further details.

Sansha city is based on what is known in English as Woody Island, part of the Paracel Islands also claimed by Vietnam and Taiwan. China took full control of the Paracels in 1974 after a naval showdown with Vietnam.

Though Sansha's permanent population is no more than a few thousand, mostly fishermen, its administrative responsibility covers China's vast claims in the South China Sea and its myriad mostly uninhabited atolls and reefs.

The state-run Vietnam News Agency said Vietnam had protested against the Chinese decision. It cited a month-old statement by a senior official that the designation of "the so-called Sansha city" was illegal and overlapped with districts Vietnam identified as its own.

Earlier this month, hundreds of Vietnamese demonstrated in Hanoi against China's establishment of Sansha city and its invitation to oil firms to bid for blocks in offshore areas that Vietnam claims as its territory.

The South China Sea has become Asia's biggest potential military flashpoint as Beijing's sovereignty claim over the huge area has set it against Vietnam and the Philippines as the three countries race to tap possibly huge oil reserves

Southeast Asian states sought to save face on Friday with a call for restraint and dialogue over the South China Sea, but made no progress in healing a deep divide about how to respond to China's growing assertiveness in the disputed waters.

(Reporting by Ben Blanchard and Wan Xu in Beijing and Hanoi newsroom; Editing by Ron Popeski)