BEIJING, Sept. 27 (Xinhua) -- Naval and air units of the Chinese People's Liberation Army (PLA) Southern Theater Command conducted a joint training exercise in the waters and airspace around China's Huangyan Dao in the South China Sea on Sunday.

A statement from the command said the exercise is a necessary operation taken in response to the acts by certain countries that have undermined regional peace and stability.

The training exercise aims to test and enhance the combat capabilities to safeguard China's territorial sovereignty and maritime rights and interests, the statement said.

Focusing on realistic training subjects such as reconnaissance and early warning, rapid maneuver, and joint search and rescue, the exercise effectively honed the troops' naval-air coordination, rapid support and win-by-system capabilities, according to the command.

It pledged that forces of the command will stay on high alert at all times and resolutely safeguard China's territorial sovereignty and maritime rights and interests.

On the same day, the China Coast Guard (CCG) conducted drills on maritime rights protection, law enforcement, and management and control in the waters near Huangyan Dao.

The CCG's drills focused on operations such as boarding and inspection, interdiction of intrusion, and forced towing, said Jiang Lue, spokesperson for the CCG, in a statement.

The CCG will step up efforts in rights protection, law enforcement, and management and control in the waters near Huangyan Dao, and resolutely safeguard China's territorial sovereignty and maritime rights and interests, Jiang said.

China has sovereignty over Nanhai Zhudao (the South China Sea Islands), consisting of Dongsha Qundao (the Dongsha Islands), Xisha Qundao (the Xisha Islands), Zhongsha Qundao (the Zhongsha Islands) and Nansha Qundao (the Nansha Islands). Huangyan Dao is located in the Zhongsha Islands.

China has historic rights in the South China Sea. China also has internal waters, territorial sea, contiguous zone, exclusive economic zone and continental shelf, based on Nanhai Zhudao.

Nanhai Zhudao have long been widely recognized by the international community as part of China's territory.