YINCHUAN, April 14 (Xinhua) -- Cultural relics experts from across China have begun a restoration project on murals in the Xumishan Grottoes dating back over 1,500 years in northwest China's Ningxia Hui Autonomous Region.

The restoration project started in early April and is the first such project to save and restore Xumishan Grottoes murals since the Qing Dynasty (1644-1911), according to the cultural relics management bureau of Xumishan Grottoes.

The grottoes are home to 185.47 square meters of murals, which are in dire need of repair due to weathering and human damages, said Wang Xi, head of the bureau.

"The repair team consists of cultural relic experts from across China and they will maintain the original style of the murals as much as possible," Wang said.

The project is expected to last a year. The bureau will record the information of murals in detail to lay the foundation for future studies, Wang said.

The Xumishan Grottoes, which were initially built in the late period of the Northern Wei Dynasty (386-534), have 162 caves and more than 1,000 statues and were listed as a key state-level cultural site in 1982.