As the torch shed light on the tomb wall, they saw five Khitan warriors on horseback raising whips and drawing bows as they hunted a red tiger.

"The precious frescoes in Liao Dynasty (916-1125) tombs, painted with minerals, are still colourful and vivid today," Shao said.

The fresco images of the Khitans were significant as the Khitans prospered in northern China and were the ruling class of the Liao Dynasty.

Shao and his colleagues at the museum of Aohan Banner in Chifeng in North China's Inner Mongolia Autonomous Region have worked on the preservation of Liao tomb frescoes for more than 30 years.

A new museum is currently being built next to the old one in Chifeng and is expected to be larger and can house more artifacts.

The area is a treasure trove of Liao tomb frescoes.

"The frescoes are so precious that each alone could be a national treasure," Shao said.

"It's a pity that the frescoes rapidly erode when a tomb is opened and oxygen enters. The only way to preserve the frescoes is to remove them from the wall," he added.

Once, when a Liao tomb was accidentally opened, Shao and his colleagues hurried inside, took photos of the frescoes, and cleaned the wall with water.

They then painstakingly painted a special glue on the frescoes and covered it with a white cloth.

When the cloth was removed, the frescoes were removed along with it. After soaking the cloth and a bit of cleaning, a complete fresco was transferred off the tomb wall.

"The process sounds simple, but it actually involves a lot of skill and experience," Shao said.

Most of the frescoes depict hunting or entertainment scenes from the Liao Dynasty. Eagles often appear in the frescoes.

A fresco in the museum's collection, called the "Eagle Army," depicts a great marching army. Leading the army was a giant flag with a hovering eagle. In the distance a military band beats their drums.

"The frescoes in Liao tombs provide valuable clues to historical research. To preserve them, we have to have more funding and more advanced techniques," Shao said.

(China Daily October 30, 2002)