The building of lighthouses on the Nansha Islands will enhance navigational safety in the South China Sea and will help fulfill China's international obligations, the Chinese foreign ministry said Tuesday.

The South China Sea is a vital waterway for international transportation and one of the most important fishing grounds in the world, said Chinese foreign ministry spokeswoman Hua Chunying at a regular press briefing.

China's construction of lighthouses on the Huayang Jiao and Chigua Jiao islands is an initiative of the country to meet its international responsibilities by providing passing vessels with efficient guidance and substantially improving navigational safety in the South China Sea, Hua stressed.

"The Chinese side will continue to build other civilian facilities on relevant maritime features of the Nansha Islands and offer better services to vessels from littoral countries of the South China Sea and those sailing through this area," she said.

The Ministry of Transport hosted a ceremony on Tuesday to mark the start of work on the two multi-functional lighthouses on the pair of islands.

According to the ministry, the lighthouses will be 50 meters high, and have a range of 22 nautical miles when completed.

Wang Xiaopeng, an expert in maritime and border studies at the Chinese Academy of Social Sciences, told the Global Times that the lighthouses will be used as public facilities for the international community, and that this project is necessary as the region is a dangerous shipping area because of its strong ocean currents.

"Building lighthouses is indeed a move to satisfy international and regional needs, while the construction is lawful as China is building on its own territory," he said.

In April, the Philippines expressed its alarm about Chinese construction activities in the area and said the building work has damaged the environment.

China rejected this accusation and said that before the construction work began the plans went through years of scientific assessment and it will inflict no damage to the marine environment.

China has repeatedly stated that the main areas advanced by its construction projects in the South China Sea are related to civilian activities.