Vietnamese officials say they have met with Chinese counterparts to formally protest the activities of a research vessel in the South China Sea off its coasts.
State media Tuesday quoted a foreign ministry spokeswoman as saying Vietnam regards the Chinese activities as a violation of its sovereignty and jurisdictional rights. The spokeswoman said Vietnam demands that China immediately cease and refrain from repeating similar acts.
China's official Xinhua news agency reported earlier that the Chinese research vessel Tan Bao Hao conducted a survey between June 13 and July 30. It said the survey took place in waters stretching from the western part of the Paracel islands to the northern part of the Spratly island chain.
China and Vietnam have conflicting claims to both island chains.
The dispute has flared in recent months, with each country issuing warnings to the other. Vietnam claims that on two occasions, Chinese vessels have interfered with Vietnamese ships exploring for oil and gas off its coasts. The Philippines is engaged in a similar dispute with China.
Malaysia, Brunei and Taiwan also have overlapping claims in the South China Sea, which is believed to be rich in oil and gas reserves.