Residents near a reservoir in Shanxi province have been evacuated after part of its dam wall collapsed, causing flooding, Xinhua reported yesterday.
The top of an irrigation duct at the Quting reservoir in Hongtong county caved in on Friday morning, leading to the partial collapse of its dam walls, the report said, citing an unidentified local official.
No casualties have been reported and it was not clear how many residents were affected.
Officials said the irrigation duct was built in 1959 and attributed its collapse to its age.
Workers sent to the scene by the Ministry of Water Resources used sandbags and other materials to seal the breach.
A China News Service report said train services through the county had been suspended at Linfen , which administers Hongtong. A video clip circulating on the internet shows hundreds of passengers queuing at Linfen railway station to have their tickets refunded.
"The train stopped in Linfen for several hours because of an emergency at a dam in Hongtong. Some passengers have started insulting train conductors," Sina microblogger Yang Jie Zai Long Shang wrote yesterday.
Three hours later he wrote: "The train started again and will take another route for passengers travelling to Taiyuan . Other passengers are getting off the train and taking the bus."
The dam is described as medium-sized, with a capacity of 19 million cubic metres.
The water level in the dam dropped one metre on Friday, the report said.
State media reported that Shanxi governor Li Xiaopeng , the son of former premier Li Peng , had issued "many important instructions" to emergency workers, and that two of his deputies visited the site in person to lead the operation.
The accident comes a month after the Shanxi government was criticised for covering up two industrial disasters, including a toxic chemical spill that contaminated drinking water for hundreds of thousands of residents living downstream in Hebei province.
The provincial government, led by Li when he was acting governor, waited five days to issue a public warning after nine tonnes of the industrial chemical aniline spilled into the Zhuozhang River last month.
The Shanxi government was also criticised for waiting eight days to confirm a December 25 explosion that killed at least eight workers at a tunnel construction site in Linfen.
The government only confirmed the blast after a torrent of online criticism.