HAIKOU - Archaeologists have discovered 12 underwater cultural relics sites near the Xisha Islands in the South China Sea, an official with the provincial government of Hainan said Sunday.

The sites were found during a 400-km patrol on the protection of underwater cultural relics and law enforcement in the area, which was jointly carried out by cultural workers from across the country. A total of 260 diving activities lasting 220 hours were recorded during the patrol.

The archaeologists examined 12 known cultural relic sites and found 12 new sites, collecting a large quantity of specimens, including ancient pottery and porcelain wares, copper coins and boat parts, said Li Jilong, an expert with the provincial cultural heritage bureau.

The Xisha Islands consist of a cluster of about 40 islets, sandbanks and reefs. During ancient times, many Chinese merchant ships struck the reefs and sank while sailing to Southeast Asia, India and the Middle East, leaving abundant treasures and cultural relics in the sea.

The archaeologists also discovered that illegal salvaging of underwater cultural relics in the South China Sea has been rampant, and traces left by thieves in some relic sites show that large-scale thefts were conducted there early this year.