India has declared itself ready to deploy naval vessels to the South China Sea to protect its oil-exploration interests there, a potential new escalation of tensions in a disputed area where fears of armed conflict have been growing steadily.
India's naval chief made the statement on Monday 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.
Petrovietnam said the seismic vessel, Binh Minh 02, had been 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 (ONGC) has a stake in a Vietnamese gas field.
Indian Navy Chief Admiral 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.
"Now, are we preparing for it? Are we having exercises of that nature? The short answer is yes," he said.
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 was quoted as saying.
Tensions have simmered in the South China Sea for many years but have escalated this year as an increasingly powerful China, which sees virtually the entire sea as its territory, begins to assert its long-standing offshore claims more vigorously.
Parts of the South China Sea are also claimed by the Philippines, Vietnam, Brunei, Malaysia and Taiwan. The region, Asia's biggest potential military troublespot, 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 said police in southern Hainan province would board and search ships which illegally entered 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 two rapidly growing 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.
Admiral Joshi described the modernisation of China's navy as "truly impressive" and a source of major concern for India.
"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," said Brahma Chellaney, an analyst at the Centre for Policy Research, in New Delhi.
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 neighbours 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 behaviour," 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-defence.
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 metres of natural gas a year from the South China Sea by 2015.
It said the South China Sea would "form the main part" of China's offshore gas exploration plans.