The Chinese government will construct lighthouses on five South China Sea islands, the state-run China News Agency reported Thursday.

Technical staff conducted thorough survey work and measurement of the waters around the islands for eight days starting July 27, the report said, citing Yang Qing, a Maritime Safety Administration official. They have confirmed the initial construction sites for the lighthouses, according to the report.

The five locations for the lighthouses include Drummond Island, North Reef and Antelope Reef, the report said. The workers will continue the survey work and collect geological samples to obtain more detailed data on the area, according to the report, which didn't say when construction will start.

China claims much of the South China Sea, which may be rich in energy and mineral deposits, under its "nine dash-line" map first published in 1947. The area extends hundreds of miles south from China's Hainan Island to equatorial waters off the coast of Borneo, taking in some of the world's busiest shipping lanes.

The area overlaps claims from Vietnam, Malaysia, the Philippines and Brunei. In the adjacent East China Sea, China contests islands administered by Japan.