A newly launched satellite will help China protect its maritime interests, the official China Daily newspaper reported on Thursday amid growing tensions over disputed territory in the South China Sea.

The "Gaofen 3" satellite that was launched on Wednesday has a radar system that captures images from space with a resolution down to 1 metre (3 feet) and can operate in all weathers, the State Administration of Science, Technology and Industry for National Defence told the newspaper.

"The satellite will play an important role in monitoring the marine environment, islands and reefs, and ships and oil rigs," the China Daily said, citing project leader Xu Fuxiang.

"Satellites like the Gaofen 3 will be very useful in safeguarding the country's maritime rights and interests," he added, according to the newspaper.

In July, an international court in The Hague ruled against China's claims in the resource-rich South China Sea in an action brought by the Philippines, a decision stridently rejected by Beijing.

China claims most of the South China Sea, through which $5 trillion in ship-borne trade passes every year.

Vietnam, China and Taiwan claim all of the disputed Spratly islands in the South China Sea, while the Philippines, Malaysia and Brunei claim some of the area.

Reuters reported this week that Vietnam had discreetly fortified several of its islands in the South China Sea with new mobile rocket launchers.

That followed satellite photos in July that showed China appeared to have built reinforced aircraft hangars on some of the disputed islands.