Playing down the significance of the exercises, the Chinese military said the drills, started yesterday in the east of Hainan Province, are not directed against neighbours.
"The drills are regular military exercises scheduled in the annual plan, without targeting any other country," the Ministry of National Defence said.
"Unlike US military forces that can be trained in wars, Chinese navy strength, which lags behind ground forces, needs to be enhanced via regular drills," Maj Gen Xu Guangyu, senior consultant at the China Arms Control and Disarmament Association, told the state-run Global Times.
Vietnam, the Philippines, Malaysia, Brunei and Taiwan strongly contest China's claims of sovereignty on almost all of South China Sea. Maritime tensions went up high in the region after the US started backing the five nations to stand up to China's claims.
The Chinese drills came after increasing tensions in the waters caused by a spate of incidents involving the US, Japan and the Philippines.
Philippine Foreign Ministry spokesperson Charles Jose said the ship is "for the safety of its personnel and safety of navigation."
According to a CNN report in May, a US surveillance aircraft received eight warnings from the Chinese navy, asking the plane to leave as it swooped over some of the islets of the Nansha Islands chain in the South China Sea.
The US and Japan also conducted separate military drills with the Philippines in the South China Sea in June, signalling two major countries' support for Manila.
Wang Xiaopeng, a maritime border expert at the Chinese Academy of Social Sciences, noted that the speculation is intended to "internationalise" South China Sea issues and to "hype the China threat theory."
In 2013, the Philippines filed an arbitration case to The Hague questioning the maritime boundaries claimed by China.
