Vietnam announced the start a live-fire naval exercise off its coast Monday amid rising tensions with China over competing claims in the South China Sea.

Vietnamese naval officers said the exercise would continue for at least six hours around Hon Ong, an unoccupied island about 40 kilometers off the coast of central Quang Nam province and about 250 kilometers from the Chinese-controlled Paracel Islands. The navy said the drill involved artillery and other weapons, but no missiles would be fired.

Vietnamese officials described the drill as a routine training exercise. But Chinese state media called it a test of Beijing's resolve after two recent incidents in which Chinese vessels interfered with oil exploration ships operating within an area Vietnam claims as its exclusive economic zone.

About 100 people staged an anti-Chinese protest in Hanoi Sunday for the second successive week. China claims jurisdiction over the waters where the incidents took place and has warned Vietnam not to provoke matters.

Vietnam charges that in the first incident late last month, Chinese naval vessels deliberately cut a cable trailing from an exploration ship. China says the second incident was an accident in which a fishing boat became entangled in an exploration cable.

The two counties have long been at odds over the Paracel and Spratly island chains in the South China Sea, which is believed to be rich in oil and gas reserves.

China, Vietnam, the Philippines, Malaysia, Brunei and Taiwan all claim South China Sea territories.