"As repeatedly emphasized, Vietnam has full legal basis and historical evidence to assert its sovereignty over the Hoang Sa [Paracel] and Truong Sa [Spratly] islands in accordance with international law.

"China carrying out military drills near Vietnam's Paracel Islands has seriously violated Vietnam's sovereignty over these islands," Foreign Ministry spokeswoman Le Thi Thu Hang said in a statement Wednesday.

"On August 7, representatives of Vietnam's Foreign Ministry had exchanges and delivered a diplomatic note opposing China's violations," Hang added.

China held illegal military training exercises near the Paracel Islands in the South China Sea, which Vietnam calls the East Sea, from 9:30 a.m. to 11:30 a.m. and from 3 p.m. to 6 p.m. on Tuesday, as well as from 3 p.m. to 5 p.m. Wednesday.

In an announcement issued Monday, the Maritime Safety Administration of China's Hainan Province said that all vessels were forbidden from entering the area while the drills were underway.

The latest drill was a continuation of similar illegal actions by China. In May last year and March this year, it had live-fire drills in areas under Vietnam's sovereignty near the Paracel Islands, which China had seized from then-South Vietnam regime by force in 1974 and has since been occupying illegally.

Last June, it held a five-day military drill in an area north of Vietnam's Spratly Islands, parts of which have been illegally occupied by China since 1988.

China's latest military drills were held even as the international community has expressed concern over its recent actions in the South China Sea.

China sent oil survey ship Haiyang Dizhi 8 and its escorts to Vietnamese waters near the Vanguard Bank in early July, blatantly infringing upon Vietnam's exclusive economic zone and continental shelf.

Satellite images taken in June also showed that China had illegally deployed at least four J-10 fighter aircraft to Vietnam's Woody (Phu Lam) Island, the largest island in the Paracels archipelago.

China claims almost the entire South China Sea, including waters close to Taiwan and Southeast Asian countries Brunei, Malaysia, the Philippines and Vietnam.

In 2012 it established the so-called Sansha City on Woody Island, which also covers several island groups and atolls in the South China Sea including the Paracel Islands, the Spratly Islands and the Scarborough Shoal.