The Tourism Administration Bureau of Xi'an has apologized for suggesting that while its city wall has stood for more than 600 years, walls in Nanjing and Beijing had disappeared long ago.

After the comment was posted on the micro blog of the Tourism Administration Bureau of Xi'an, Shaanxi province, a number of residents in Nanjing, Jiangsu province, complained online that the ancient city wall in Nanjing not only still stands but has been around longer than the one in Xi'an.

"I do not know what you mean that the ancient city wall in Nanjing disappeared," a Nanjing netizen said.

Later on Tuesday afternoon, the micro blog of the Nanjing Ancient City Wall Protection and Management Center said the comments were irresponsible and created a loss of public trust.

"The ancient city wall in Nanjing is 25 km long, and most of it is original," the center said. "You should verify something before you say it."

Beijing's city wall also stood for hundreds of years before being mostly torn down in the 1950s and 60s. However, some remnants remain.

The Xi'an tourism administration bureau later deleted the post and apologized for the error.

A senior official of the Xi'an tourism bureau made a phone call to the center on Wednesday apologizing for the post, according to Cao Fangqing, deputy chief of the Nanjing center's Party committee.

Cao said that Nanjing and Xi'an are working with six other Chinese cities that have ancient city walls to declare them part of the world's cultural heritage.

Cao said the declaration will be presented to the State Administration of Cultural Heritage in March, and that Nanjing will be chosen as the lead city for the declaration because it is the only one of the eight that was a royal capital while the walls were standing.

Nanjing was the capital during part of the Ming Dynasty (1368-1644). The city wall was built from 1366 to 1393 and had a total length of 36.27 km, of which 25.1 km still stands.

The city wall in Xi'an was also built in the Ming Dynasty with a total length of 13.74 km. It is one of the symbols of the city and a popular tourism spot known worldwide.

He Yun'ao, a professor of history at Nanjing University, said that the city walls of Nanjing and Xi'an are priceless cultural relics.

"They have their own characteristics and do not need to compete for No 1 in China," the professor said.

By Ma Lie in Xi'an (China Daily)