BEIJING -- China and two of its neighbors, Vietnam and India, were locked in a new dispute Tuesday over energy exploration in the South China Sea, a signal that Beijing plans to continue its hard line in the increasingly contentious waterway.
Vietnam accused a Chinese fishing boat of cutting a seismic cable attached to one of its vessels exploring for oil and gas near the Gulf of Tonkin, an act apparently designed to inhibit Vietnam from pursuing energy deposits. In retaliation, Vietnam said Tuesday that it would launch new patrols, to include marine police, protecting against Chinese fishing boats' increasing encroachment in the South China Sea.
India, which operates several joint ventures with Vietnam's national energy company, Petro Vietnam, said it, too, would consider sending navy vessels to protect its South China Sea interests.
The latest episode follows an announcement by Hainan province in southern China last week that Chinese vessels would board and search ships in contested areas of the waterway, which includes vital shipping lanes through which more than a third of global trade moves.
The new tensions among China, Vietnam and India illustrate in stark terms the competition in the South China Sea for what are believed to be sizable deposits of oil and gas. Some energy experts in China see the sea as an important new energy frontier close to home that could make China less dependent on its huge Middle East oil imports.
On Monday, China's National Energy Administration named the South China Sea as the main offshore site for natural gas production. Within two years, China aims to produce 150 billion cubic meters of natural gas fields in the sea, a significant increase from the 20 billion cubic meters produced so far, the agency said.
Earlier this year, China's third-largest energy company, state-owned China National Offshore Oil Co., launched new equipment that would allow China to drill in deep water for the first time. Since then, CNOOC has been drilling with a rig in deep water in non-disputed waters off the southern coast of China.
The South China Sea escalation comes less than a month after Xi Jinping took office as China's leader. Mr. Xi appears to have taken a particular interest in the South China Sea and the serious dispute between China and Japan over the islands known as Diaoyu in China and as Senkaku in Japan. Whether any of China's most recent South China Sea actions were associated with Mr. Xi was unclear.
But Mr. Xi does lead a small group of policymakers clustered in the Maritime Rights Office, which serves to coordinate agencies within China, according to Peking University international relations professor Zhu Feng and other Chinese experts. The unit is part of the office of the Foreign Affairs Leading Small Group, Mr. Zhu said. The leading small group, now headed by Mr. Xi, is widely believed to be China's central policymaking group.
China's Foreign Ministry reiterated Tuesday that China opposed oil and gas development by other nations in disputed waters of the sea. China maintains that it has "undisputed" sovereignty over the South China Sea, and that only China is allowed to develop the energy resources. "We hope that concerned countries respect China's position and rights," Foreign Ministry spokesman Hong Lei said.
Vietnam, which has long been wary of China but enjoys a relationship through its governing Communist Party, summoned the Chinese ambassador Monday to protest the seismic cable's cutting, the Vietnamese press reported.