MANILA, Philippines (UPDATED) - The Philippines and Vietnam on Tuesday lashed out at China's moves to establish a military garrison in the South China Sea, amid escalating tensions in the disputed waters.
The Philippines summoned the Chinese ambassador to Manila, while Hanoi filed a formal protest with Beijing against the plan outlined by China this week to station troops in Sansha in the disputed Paracel Islands, saying it "violates international law".
The Department of Foreign Affairs (DFA) said it summoned Ma Keqing to lodge the complaint, and also to object to the arrival of a military-escorted Chinese fishing fleet near the contested Spratly Islands.
The Chinese defense ministry announced plans to operate troops from Chinese-held Sansha or Woody Island in the Paracels on Monday.
While the Philippines does not have territorial claims on the Paracels, DFA spokesman Raul Hernandez said the Chinese plan to administer both island groups from Sansha was unacceptable.
"The Philippine government has expressed its grave concern and registered its strong protest over the Chinese government decision to establish a military garrison in Woody Reef," Hernandez told reporters.
China claims sovereignty over nearly all of the South China Sea, which is believed to hold vast amounts of oil and gas, while the Philippines, Taiwan, Brunei, Malaysia and Vietnam each claim portions.
Disputes have flared in recent weeks, with Vietnam and the Philippines criticizing what they call Chinese encroachment.
The Philippine coast guard monitored a fleet of 29 fishing vessels, a cargo vessel, and three other ships including one Chinese navy vessel near Fiery Cross Reef and Subi Reef on July 18, Hernandez said.
"The use of armed government vessels to escort fishing vessels that conduct non-fishing activities is a violation of Philippine territory and a violation of obligation of states under international law," Hernandez said.
Vietnam: China garrison plan invalid
Beijing's garrison plan "violates international law, seriously violates Vietnam's sovereignty... and is invalid," Vietnamese Foreign Ministry spokesman Luong Thanh Nghi told AFP.
China attracted Hanoi's ire -- and sparked a series of rare protests in the Vietnamese capital -- when it last month designated Sansha as its administrative centre for the Paracels and the Spratly Islands.
The state-backed China National Offshore Oil Corporation also announced it was welcoming bids to explore oil blocks in the disputed waters, a week after Vietnam adopted a law placing the Spratlys under its sovereignty.
Nghi told AFP Tuesday that China must revoke its "wrongdoings" and urged "friendly and cooperative" relations in order to "maintain peace and stability" in the South China Sea.
China and South Vietnam once administered different parts of the Paracels but after a brief conflict in 1974 Beijing took control of the entire group of islands. Vietnam still holds several of the larger Spratlys.
A July 13 meeting of the Association of Southeast Nations broke up without a joint statement for the first time in 45 years because members could not agree on how to refer to China's behaviour in the disputed waters.
The countries are drafting a "code of conduct" to try to prevent flare-ups in the area.
Meanwhile, Taiwan, which is one of several claimants to portions of the Spratly chain, also plans to boost firepower at its base on that archipelago's biggest island Taiping from next month, Taipei's coastguard said on Tuesday.
Longer-range artillery and mortars are to be added to existing weaponry at the site, in a move that could further stoke tensions in the region.