The death toll rose from nine after four children who were hospitalized died, and one child who had been missing was found dead, the Xinhua news agency reported. 

The cause of the accident is still under investigation, but a spokesman with the city government's information office said the weather was very foggy when the vehicle plunged into the body of water. 

The incident happened in the Songjiang Township of Hengnan County, a county education bureau spokesman told Xinhua.