Chinese officials are investigating what caused a bridge under construction in an ancient Chinese city to collapse killing at least 29 people.

The 268-metre bridge spanning the Tuo River in Hunan province collapsed Monday as 123 workers removed scaffolding from its facade, state television reported Tuesday.

Rescuers search for victims at the site of a collapsed bridge in Fenghuang, in central China's Hunan province, on Tuesday.Rescuers search for victims at the site of a collapsed bridge in Fenghuang, in central China's Hunan province, on Tuesday.
(Associated Press)

Twenty-two people were injured but 86 were rescued, according to the official Xinhua News Agency.

The 43-metre high bridge in Hunan's Fenghuang County had four decorative stone arches and was scheduled to open as a tourist attraction at the end of this month, Xinhua said. 

Most of the people working on the bridge were reportedly local farmers.

The bridge was a $1.6-million project by the Fengda company of western Hunan, according to Xinhua.

Xinhua identified the contractor as the state-owned Hunan Road and Bridge Construction (Group) Ltd. Co., or RBC.

In its annual report on road safety last year, the Ministry of Communications categorized 6,300 of the country's bridges as dangerous because of serious damage to their "structural components," the China Daily newspaper reported Tuesday.

With files from the Associated Press