Renovators of the ancient city walls in Xi'an are in for a busy time after a 30-meter section they were working on partly collapsed on Tuesday.

Workers blamed recent heavy rain for the mishap.

The section of the wall between the South Gate and Wenchang Gate subsided at 11:00 am, and according to local resident Lao Liu: "It cracked as if it were hit by an earthquake."

No one was injured and the site was immediately cordoned off in case of further collapse, an official surnamed Wang from the city's wall administrative committee, told China Daily yesterday.

"We have been renovating this section since the beginning of July and the bricks of the wall were moved," he said. "Without the support of the bricks, the earth inside the wall was softened."

Workers had taken measures to avoid such a collapse by adding supporting pillars, but the recent rain made the renovation much more difficult, Wang said.

The wall in Xi'an, capital of Shaanxi Province, was built in 1370 and is the largest and best-preserved wall in the world. It stretches 13.75 kilometres around the city and is 15 metres high at the top. The wall was constructed with compressed earth and then covered by bricks.

Over time the wall's condition deteriorated, but in 1983 the local government started a rebuilding and renovation project. However, some sections were renovated with red bricks, which were not used in the original construction.

To rectify this, the local government began working again on the collapsed section, replacing it with ancient-style bricks, Wang said.

The collapse will not slow down the project, which is expected to be completed before October, he said.

(China Daily July 27, 2006)