The death toll from a bridge collapse in Central China's Hunan Province has risen to 36, with at least 23 still missing, rescuers said yesterday.

The 328-m-long, 42-m-high Tuojiang River Bridge in Fenghuang County, in the western part of the province, collapsed on Monday afternoon when an estimated 123 workers were dismantling its steel scaffolding.

Sixty-four workers escaped or were rescued. Twenty-two are still in hospital receiving treatment for their injuries.

At Fenghuang Traditional Chinese Medicine Hospital, three seriously injured workers are no longer described as in critical condition after receiving emergency treatment, hospital sources said. Seventeen workers are receiving treatment at the hospital.

President Hu Jintao yesterday asked the authorities to "draw deep lessons" from the accident and strive to improve production and work safety.

Those responsible for the incident will be "severely dealt with", he warned while paying a state visit to Kyrgyzstan.

In Fenghuang, more than 1,500 rescuers are still searching the debris, but medical workers said there was little chance of finding survivors.

A nine-member team of experts has arrived at the site to take samples from the rubble to determine whether the bridge had structural problems.

Meanwhile, an investigation team under the State Council has been set up. The team, headed by Li Yizhong, minister of the State Administration of Work Safety, consisted of officials from the communications, construction, health and supervision ministries.

While the cause of the collapse is still unknown, a local official at the scene claimed that a "traditional and risky" model of bridge, made of stone and concrete, had been chosen over a steel structure to ensure "it remained in harmony with the natural environment".

"No reinforced steel bars were seen in the collapsed bridge supports. It was like a knife cutting through tofu," rescue worker Hou Jiaping was quoted as saying by Beijing Times.

Two officials from the builder, the state-owned Hunan Road and Bridge Construction Co, have been taken into police custody. The Xinhua News Agency said the company was also contracted to build Jiujiang Bridge in South China's Guangdong province, which collapsed on June 15 after a cargo vessel ploughed into it, killing nine people.

The four-arch bridge was to link Fenghuang County, a popular tourist spot, with Daxing airport in Tongren city, in neighboring Guizhou Province.

Construction began in March 2004 and the bridge had been scheduled to open to traffic at the end of the month.

Police have detained Xia Youjia, a construction manager, and Jiang Ping, a project supervisor. All technical data about the bridge and financial accounts of the companies involved have been sealed for examination.

The collapse also affected water supplies to about 700,000 residents in Fenghuang as pipes at the local water plant were broken by falling debris. The supply resumed yesterday afternoon.

Medical workers have disinfected the section of the Tuojiang River near the accident site to limit the chances of a disease outbreak.

Xinhua contributed to the story