HANOI, May 29 (Reuters) - Vietnam accused China on Sunday of increasing regional tensions and said its navy would do everything necessary to protect its territorial integrity after Chinese patrol boats interfered with a Vietnamese oil and gas survey ship in the South China Sea.
The remarks appeared to raise the stakes in the latest row over long-standing conflicting maritime claims just days before a regional defence summit in Singapore and highlight nervousness about China's growing assertiveness in the region.
In a rare weekend news conference, Vietnamese officials rejected China's claims that the Vietnamese ship conducting a seismic survey was in Chinese waters. The incident happened about 120 km (80 miles) off the south-central coast of Vietnam and some 600 km (370 miles) south of China's Hainan island.
"The Vietnamese navy will do everything necessary to firmly protect peace and the independence, sovereignty and territorial integrity of Vietnam," foreign ministry spokeswoman Nguyen Phuong Nga said.
Do Van Hau, deputy chief executive of state oil and gas group Petrovietnam, which was operating the ship, said one of three Chinese patrol vessels on the scene intentionally cut a submerged cable towed by the ship, the Binh Minh 02. It was not the first time Chinese ships had cut cables of Vietnamese survey boats, he said.
The Chinese boats then threatened the Vietnamese ship with violence, he added without elaborating.
China, Vietnam, the Philippines, Malaysia, Brunei and Taiwan all claim territories in the South China Sea, which cover an important shipping route and are thought to hold untapped oil and gas reserves. [ID:nSGE6950BX]
China's claim is by far the largest, forming a vast U-shape over most of the sea's 648,000 sq miles (1.7 million sq km), including the Spratly and Paracel archipelagos.
"The fact that China is trying to find ways to realise (its territorial claims) is clearly increasing the tension in the region," said Nguyen Duy Chien, vice chairman of the Vietnamese foreign ministry's national boundary commission.
China blamed Vietnam on Saturday for the incident, saying such Vietnamese oil and gas operations undermined China's interests and jurisdictional rights.
Chinese Foreign Ministry spokeswoman Jiang Yu said the behaviour of "the relevant Chinese departments" in the incident was normal. [ID:nL3E7GS07E]
Defense ministers from around the Asia-Pacific region meet in Singapore from June 3-5. (Reporting by John Ruwitch; Editing by Nick Macfie)