BEIJING - China's president has called for severe punishment against those responsible for a bridge collapse that killed at least 40 people, state media said Thursday.

Rescuers combed through the rubble of the bridge in the southern tourist town of Fenghuang searching for about two dozen people missing since Monday's collapse.

The official Xinhua News Agency said the death toll had reached 40 and the chances of finding more survivors were slim.

But all efforts should be made to find the missing and to take care of the 22 injured, Xinhua quoted President Hu Jintao as saying.

Authorities must "immediately set up a panel to investigate into the cause of the accident and bring those responsible" to justice, Hu was quoted as saying in Kyrgyzstan where he was on a state visit.

"Measures must be taken to ensure lessons are learnt from the accident so that similar accident shall not happen again," Hu said.

Hua Jianmin, secretary of the State Council, China's Cabinet, personally briefed local officials on Hu's orders, Xinhua said

It was the president's first publicly reported reaction on the bridge collapse, which rekindled concerns about rushed, shoddy construction work amid China's economic expansion.

Earlier this week, Premier Wen Jiabao called for a thorough investigation into the collapse, saying those responsible would be "severely dealt with."

Two officials from the builder, state-owned Hunan Road and Bridge Construction Co., have been detained.

The bridge had been nearing completion when it fell. State media said 123 construction workers were on the 140-foot-high, 880-foot-long bridge removing scaffolding when it collapsed.

Survivors say that there had been concerns among the workers about the large size of the four stone arches capping the bridge and the lack of steel reinforcements in the structure, which consisted mainly of stone and concrete.

Xinhhua said a State Council team headed by Li Yizhong, China's top industrial safety official was investigating problems with the project's "design, public bidding, construction, management or construction supervision."

Construction began in March 2004, with the bridge due to open to traffic linking the town to a nearby airport at the end of this month.

Xinhua quoted an unidentified local official as saying the stone and concrete bridge had been chosen over a safer and more modern steel structure to ensure "it remained in harmony with the natural environment."