Vietnam has briefed India about the escalating tension in the South China Sea after China deployed a large number of survey vessels in Vietnamese waters including around areas where India's ONGC has oil exploration projects.
On July 4, Chinese survey vessel Haiyang Dizhi 8, escorted by a large number of ships including from the coast guard began conducting marine seismic surveys near several offshore oil blocks which fall within Vietnam's exclusive economic zone, Vietnamese diplomatic sources said.
The Chinese action aimed at disrupting oil exploration projects in Vietnam's waters triggered the biggest confrontation between the two neighbours since 2014 and Vietnam is determined to protect its territorial integrity, they said.
An attempt by China in 2014 to drill oil in the Paracel Islands, claimed by Vietnam, had led to anti-China riots in Vietnam in which several Chinese factories were vandalised.
The sources said China had deployed as many as 35 ships to escort Haiyang Dizhi 8, a ship operated by the China Geological Survey.
"We have briefed India about the current situation in South China sea as it is a major stakeholder and a key player in the region," said a Vietnamese official on the condition of anonymity.
China claims sovereignty over all of the South China Sea, a huge source of hydrocarbons. However, several ASEAN member countries, including Vietnam, Philippines and Brunei, have counterclaims.
China has been objecting to India's oil exploration projects in the Vietnamese waters in the South China Sea.
India has been supporting freedom of navigation and access to resources in the South China Sea in accordance with principles of international law, including the 1982 UN Convention on the Law of the Sea.
A spokesperson of Vietnam's Foreign Ministry said in Hanoi last week that the country is determined to safeguard its sovereignty and jurisdiction in the South China sea in accordance with international laws.
Besides India, Vietnam has also reached out to the US, Russia, Australia and several other leading players against the Chinese action which appeared to be aimed at disrupting oil exploration projects in Vietnam's waters, sources said.
They said China has conducted provocative activities near several oil blocks including block 06/1 where Russia's Rosneft and India's ONGC were involved for oil and gas production for close to 17 years.
"China's activities undoubtedly constitute a clear violation of international law and seriously infringe upon Vietnam's sovereign rights and jurisdiction over its waters in the area as provided in the UN Convention on the Law of the Sea (UNCLOS)," the official said.
The Vietnamese sources said Vietnam has already taken up the issue at multiple levels with Chinese government and will go for its "international judicial review" if Beijing does not retreat from its territory.