More hidden dangers have been detected on the ancient city wall of Pingyao in north China's Shanxi Province though the earlier collapsed part was renovated in May, a local cultural heritage official said.

"A total of 52 dangerous sections were recently confirmed on the 630-year-old wall which was listed as a World Cultural Heritage site in 1997 by the United Nations Educational, Scientific and Cultural Organization," said Dong Yangzhong, an official with the Shanxi Provincial Cultural Heritage Bureau.

The wall has a circumference of 6,162 meters. Of the 52 sections in a dangerous state, 26 sites are particularly vulnerable to collapse. The hidden dangers were spotted by a specialized construction institute which examined the entire wall using advanced technology, Dong said.

Experts suggested emergency measures, such as putting warning signs at the sections in dangerous states and limiting the number of tourists, should be taken immediately.

"A comprehensive protection package based on the recent examination will come out soon," Dong said.

The examination lasted more than half a year, following the first wall collapse on Oct. 17, 2004. The collapse caused no casualty because no one was around when the 17-meter long, 10-meter tall, three-meter thick section near the southern city gate fell apart.

Repair of the collapsed part was near completion in early May, costing 870,000 yuan (about 105,300 US dollars), Dong said.

The existing city wall of Pingyao was rebuilt in 1370 on the old one. Pingyao, an ancient banking and business center, has well-preserved streets, stores, temples and residential houses built during the imperial Ming (1368-1644) and Qing (1644-1911) dynasties, attracting numerous tourists from home and abroad each year.

Source: Xinhua