DUNHUANG, Gansu, June 6 (Xinhua) -- The Mogao Grottoes, a world cultural heritage site in Gansu province, will reopen to visitors Thursday after being closed for two days due to heavy rain.

A flash flood triggered by a rainstorm damaged the only highway leading to the Mogao Grottoes Tuesday morning, local authorities said.

The downpour gave rise to a sudden flood on the Daquan River, damaging a road bridge and a section of highway near a railway station in the city of Dunhuang.

The Mogao Grottoes are located 25 km south of the city. To ensure the safety of the heritage site, authorities decided to temporarily close the grottoes.

After emergency operations, the highway leading to the heritage site was repaired Wednesday, and the administrators decided to reopen the grottoes to visitors Thursday.

The Mogao Grottoes, also known as the Ancient Caves of 1,000 Buddhas, were listed in 1987 by the United Nations' Educational, Scientific, and Cultural Organization as a world cultural heritage site.

Thousands of tourists flock to see frescoes and carvings in the Mogao Grottoes every year. The grottoes are home to some of the best preserved examples of Buddhist art in China.