Chinese State television has for the first time aired China's construction work on Yongshu Reef in the Nansha Islands.

China Central Television (CCTV) on Tuesday released video of construction work on Yongshu Reef as part of a news report on the performances of a Chinese People's Liberation Army (PLA) navy song and dance troupe on the reef.

Buildings, roads and lighthouses are beginning to take shape, according to the videos.

"It is probably the first time that CCTV has publicly released video about the reef," Li Jie, a Beijing-based military expert, told the Global Times on Wednesday, stressing that the construction on the reef falls within China's sovereignty and is aimed at regional peace and stability.

In April, a Chinese patrol aircraft landed on the reef to pick up three ill construction workers, a humanitarian mission later questioned by the Pentagon for using a military aircraft instead of a civilian one.

China began to reclaim land on Yongshu Reef in August 2014, and several test flights were conducted on an airport in the reef in January, according to the Xinhua News Agency.

Meanwhile, a six-vessel flotilla belonging to the PLA navy's South China Sea Fleet on Wednesday left a port in Sanya, South China's Hainan Province for an annual live ammunition drill, which includes simulations of breaking through the blockade of "the enemy" and reconnaissance and counter-reconnaissance drills with submarine forces, Xinhua reported.

Such exposure on reef construction activities and the drills at this particular time come amid hyped-up South China Sea issues and more involvement from countries outside the region, Li said, adding that the naval exercises are part of "a targeted move to improve the Chinese navy's detection and warning capabilities."

The flotilla is scheduled to conduct drills in the South China Sea, East Indian Ocean and West Pacific. The PLA Naval Aviation of the South China Sea Fleet and troops on the Nansha Islands will also participate in the drills, along with troops from the North China Sea Fleet, according to Xinhua,

The drills are part of the PLA navy's annual training, Xinhua noted.

"The flotilla also includes the newly-built comprehensive depot ship Honghu, which can provide support for sustained combat at sea," Li noted, adding that such capabilities are vital for maritime operations, considering China's vast territorial footprint in the South China Sea.