MANILA • China is expanding artificial islands in disputed South China Sea areas despite saying it stopped two years ago, according to a security think-tank that released satellite images it said showed the land reclamation.

Beijing claims most of the sea, and has turned reefs in the Spratly and Paracel chains into islands, installing military aircraft and missile systems on them - an activity the Asia Maritime Transparency Initiative (AMTI) said is continuing.

"China's own reclamation work did not end in mid-2015 with the completion of its artificial islands in the Spratlys. Beijing continues to reclaim land farther north, in the Paracel Islands," the think-tank said on its website.

Chinese Foreign Minister Wang Yi told reporters on the sidelines of the Asean Regional Forum in Manila on Monday that Beijing completed its South China Sea reclamation activities two years ago.

"I also wanted to tell you that two years ago, China had already completed the reclamation. That is something I can tell you for sure," Mr Wang said, adding "it is not China" that is conducting ongoing reclamation activities.

The AMTI website on Wednesday posted satellite pictures that it said showed Mr Wang's statements were "false". China has, since 2015, dredged a new harbour and added 10ha of land on Tree Island in the Paracels, and has recently completed a new helipad and installed wind turbines and photovoltaic solar arrays there, it said. Since reclamation work to connect two other Paracel islands was washed out by a typhoon last October, China has undertaken additional reclamation and built new structures there, it added.

China claims nearly all of the strategically vital sea, through which US$5 trillion (S$6.8 trillion) in annual shipping trade passes and which is believed to sit atop vast oil and gas deposits.

Its sweeping claims overlap with those of Asean members Vietnam, the Philippines, Malaysia and Brunei, as well as Taiwan.

AGENCE FRANCE-PRESSE