China has completed the construction of four lighthouses on reefs in the South China Sea, and is building the fifth one, to aid sea navigation in the area, a Ministry of Transport official said on Sunday.

The four lighthouses on Huayang Reef, Chigua Reef, Zhubi Reef, and Yongshu Reef are already in operation and have significantly improved the security of vessels passing through waters in the area, said Xu Ruqing with the maritime affairs department under the Ministry of Transport.

Construction of the lighthouse on the Meiji Reef has finished its main part and further information will be released via navigation announcement, Xu said.

All of the five lighthouses are large and multi-functional with their heights between 50 meters to 55 meters. They are equipped with huge modern rotating lamp device and lanterns with a diameter of 4.5 meters. The lantern can send white light to as far as 22 nautical miles.

The five lighthouses equipped with automatic identification system (AIS) and very high frequency (VHF) stations can also work like a radiobeacon to assist navigation with information exchanges such as warnings and requests for help between the lighthouses and ships.

The construction and use of the five lighthouses demonstrated China's efforts to perform its international responsibilities and will contribute to navigation support, maritime search and rescue, navigation safety, fishery production, disaster prevention and relief and other services, according to Xu.