India's naval chief made the statement just as Vietnam's state oil and gas company, Petrovietnam, accused Chinese boats of sabotaging an exploration operation by cutting a seismic cable being towed behind a Vietnamese vessel, Reuters reported.
Petrovietnam said the seismic vessel, Binh Minh 02, was operating outside the Gulf of Tonkin when the cable was severed on Friday. It had earlier been surveying the Nam Con Son basin further south -- an area where Indian state-run explorer Oil and Natural Gas Corp. has a stake in a Vietnamese gas field.
Indian Chief Adm. D.K. Joshi said that, while India was not a territorial claimant in the South China Sea, it was prepared to act, if necessary, to protect its maritime and economic interests in the region.
"When the requirement is there, for example, in situations where our country's interests are involved, for example ONGC ... we will be required to go there and we are prepared for that," Joshi told a news conference in New Delhi.
"Now, are we preparing for it? Are we having exercises of that nature? The short answer is yes," he said.
The admiral added, “Apart from three stealth frigates, one recently commissioned nuclear-powered submarine (INS Chakra) and one of our biggest amphibious landing ships, INS Jalashva, are being deployed in the eastern naval command facing the South China Sea,” Daily News and Analysis of India reported.
Petrovietnam posted on its website comments made by the deputy head of exploration, Pham Viet Dung, to a journalist from Vietnam's Petrotimes that the seismic cable was quickly repaired and the survey resumed the following day.
"The blatant violation of Vietnamese waters by Chinese fishing vessels not only violates the sovereignty ... of Vietnam but also interferes in the normal operations of Vietnamese fishermen and affects the maritime activities of Petrovietnam," Dung said.
Tensions have simmered in the South China Sea for many years but have escalated this year as China, which claims virtually the entire sea as its territory, begins to assert its long-standing offshore claims more vigorously.
Parts of the sea are also claimed by the Philippines, Vietnam, Brunei, Malaysia and Taiwan. The region, Asia's biggest potential military trouble spot, is believed to be rich in oil and gas -- and more than half the world's oil-tanker traffic passes through it.
Last week, Chinese state media announced police in southern Hainan province would board and search ships that illegally enter what China considers its territory in the sea -- a move that immediately raised fears for the free passage of international shipping and the possibility of a naval clash.
India is not the only non-claimant nation concerned about disruption to shipping or oil exploration in the South China Sea. The United States, a close ally to several of the Southeast Asian claimants, has also voiced concern at the prospect of China stopping international ships in contested waters.
India has sparred diplomatically with China in the past over its gas and oil exploration block off the coast of Vietnam.
Any display of naval assertiveness by India in the South China Sea would likely fuel concern that the navies of the Asian giants could be on a collision course as they seek to protect trade routes and lock in the supply of coal, minerals and other raw material from foreign sources.
Joshi described the modernization of China's navy as "truly impressive" and a source of major concern for India.
He also stressed that disputes over freedom of navigation within the South China Sea must be resolved in line with international treaties, the Hindustan Times reported.
"Not only us, but everyone is of the view that they have to be resolved by the parties concerned, aligned with the international regime, which is outlined in UNCLOS (United Nations Convention on the Law of the Sea), that is our first requirement," Joshi said.
When asked to spell out the Navy’s response in case China resorts to searching vessels, Joshi said rules of engagement for that purpose remain the same, reported The Pioneer, an Indian paper.
“Firstly, we do not hope and expect that the situation would come where the rules of engagement come in play. Secondly, rules of engagement are constant, they don’t change from one area to another. In essence it is wherever your right of self defence is impended, if it is needed, then certain options are available,” he said.
"It is one of the most important international waterways and freedom of navigation there is an issue of utmost concern to India because a large portion of India's trade is through the South China Sea," Brahma Chellaney, an analyst at the Centre for Policy Research in New Delhi, told Reuters.
Chellaney, however, played down Joshi's comments, saying the Indian navy's focus would remain on the Indian Ocean, which the South Asian nation views as its strategic backyard.
Singapore, home to the world's second-busiest container port, joined some of its neighbors on Monday in expressing concern at the Chinese reports that Hainan police would board and search ships under rules to take effect from Jan. 1.
"We urge all parties to the territorial disputes in the South China Sea to refrain from provocative behavior," the Singapore government said in a statement.
Asked about the reports of China's plan to board ships, Joshi said India had the right to self-defense.
Estimates for proven and undiscovered oil reserves in the South China Sea range as high as 213 billion barrels of oil, the U.S. Energy Information Administration said in a 2008 report.
That would surpass every country's proven oil reserves except Saudi Arabia and Venezuela, according to the BP Statistical Review.
On Monday, China's National Energy Administration said China aims to produce 15 billion cubic meters of natural gas a year from the South China Sea by 2015.
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