XINING, Sept. 21 (Xinhua) -- Chinese experts have begun restoring a 700-year-old handwritten copy of the Koran, the sacred book of Islam, in northwest China's Qinghai Province.

The restoration began with a scientific analysis of the paper and ink, said Xi Sancai, director of the cultural relics preservation technique research institute with Nanjing Museum in east China's Jiangsu Province.

"We will clean up marks and mildew stains, and mend damaged pages by using the most advanced and mature technologies," said Xi, who is in charge of the three strong restoration team.

The 867-page, two-volume set, the oldest of its kind known in China, is written in Arabic and stored in two caskets in the Jiezi mosque in Xunhua County.

It was brought to China when the Salar ethnic group moved east from Maracanda, the ancient name of Samarkand in Uzbekistan, about 700 years ago. Experts believe it was completed before the 13th Century.

"The books have been seriously eroded and are in danger of rotting," said Ma Weimin, deputy director of the Qinghai Provincial Cultural Heritage Bureau.

The books have been photographed with a digital camera, in order to make replicas, said Ma.

"Local conditions, such as the lack of equipment, limit the work," said Xi. Local people were reluctant to see the books removed from the area.

But Xi said he was confident of success as the books were not severely damaged.

The team would use as few chemical materials as possible to protect the books, said Xi.

The work would be completed within the year, Xi predicted.

The State Cultural Heritage Administration has allocated 440,000 yuan (55,000 U.S. dollars) for the project.

An exhibition center near the mosque has been completed in order to display the books. The four million yuan (500,000 U.S. dollars) cost of the building came from voluntary donations by local people.

After the restoration, the books would be put into a transparent glass viewing case for visitors in the center, said Xi. Enditem