The neighbouring nations are at loggerheads over sovereignty of the potentially oil-rich Paracel and Spratly archipelagos and surrounding waters, where recent confrontations between their ships have sparked a war of words.
A Vietnamese naval officer told AFP that the six hours of live-fire exercises would be held around Hon Ong island, about 40 kilometres (25 miles) off Quang Nam province in central Vietnam.
The officer declined to give the reason for the night drill or say how many vessels would be involved, but foreign ministry spokeswoman Nguyen Phuong Nga said the exercises were part of routine annual training.
The drills will be held in the area claimed as Vietnam`s exclusive economic zone, where Hanoi last month accused Chinese surveillance vessels of cutting the exploration cables of an oil survey ship, causing tensions to rise sharply.
On Thursday Vietnam alleged a similar incident in the zone, saying a Chinese fishing boat rammed the cables of another oil survey ship in its waters, describing it as a "premeditated" attack.
Beijing countered by warning Vietnam to halt all activities that it says violate China`s sovereignty in the disputed area.
The United States said it was "troubled" by tensions triggered by the maritime border dispute, calling for a "peaceful resolution".
The area where the live-fire exercise is planned is about 250 kilometres from the Paracels and almost 1,000 kms from the Spratlys.
Carl Thayer, a veteran analyst of Vietnam and the South China Sea, said that the drill would be a way for Vietnam to send a message, after China a day earlier also said it would conduct naval exercises.
Thayer said Vietnam was firing "a soft warning shot across the bow, rather than a real one."
But he added such drills were not unprecedented because Vietnam held an air-defence drill on land about two months ago.
Beijing says it is committed to peace in the South China Sea, but its more assertive maritime posture has caused concern among regional nations and beyond.
Tensions have also risen this year between China and the Philippines, another claimant to the Spratlys, where Malaysia, Brunei and Taiwan also say they have a stake.
In Vietnam, where protests are rarely held, hundreds of citizens in southern Ho Chi Minh City and in Hanoi held anti-China rallies on Sunday, bearing signs proclaiming Vietnamese sovereignty over the disputed archipelagos.
Vietnamese bitterly recall 1,000 years of Chinese occupation and, more recently, a 1979 border war. More than 70 Vietnamese sailors were killed in 1988 when the two sides had a battle off the Spratlys. (*)
Editor: Kunto Wibisono
Copyright © ANTARA 2011
