HOHHOT, Aug. 21 (Xinhua) -- A north China museum has worked with a Swiss foundation to successfully restore 14 pieces of silk relics unearthed from tombs with over 1,000 years of history, sources with the museum said Sunday.

Since 2010, the Inner Mongolia Museum and the fabric restoration and research center of the Switzerland-based Abegg Foundation have conducted research and repaired antique silk costumes, said Tala, director of the museum.

The costumes were discovered in 1991 from a cluster of nine tombs that were built in the Liao Dynasty (907-1125), also known as the Khitan Empire, according to Tala.

The tombs, located in Horqin Right Wing Middle Banner (county) of Inner Mongolia Autonomous Region, are believed to have belonged to Khitan nobles.

Tala said the cooperation of the two sides will lay the foundation for further research on antique fabrics and shed light on ancient culture of the Liao Dynasty.