A team of archaeologists has embarked on a mission to excavate a shipwreck near Shanhu Island in the Xisha archipelago in the South China Sea, local authorities said on Monday.

The 25-strong team set off on a 45-day journey from Qinglan Port in Wenchang, Hainan province, on Sunday, according to a spokesman for the provincial Cultural Heritage Administration.

This is the second large-scale underwater archaeological mission in the South China Sea following the 2008 study of a vessel loaded with porcelain that sank more than 700 years ago off the Huaguang reef near the Xisha Islands.

The team will carry out an underwater survey of a second sunken ship near Jinyin Island in the archipelago, the spokesman added.

The sites contain a substantial amount of stone building materials and carvings dating from the Qing Dynasty (1644-1911).

The Shanhu Island site, which is 2,000 meters from the island, covers 20,000 square meters, and the water depth ranges from two to seven meters.

The other site is 2,500 meters from Jinyin Island, covers 45,000 square meters and lies at a depth of between three and nine meters.

China has located more than 120 shipwrecks around the Xisha, Nansha and Zhongsha islands.