At least 18 people died and 37 were injured after an overloaded bus plunged 10 metres from a bridge into a ravine in a mountainous area of south-western China, dpa quoted state media as saying on Thursday. The passenger bus fell from the bridge late Wednesday on an icy stretch of expressway in Guiding county, Guizhou province, a local government spokesman was quoted as saying. At least six of the 37 injured remained in critical condition on Thursday, reports said. State television showed the 53-seat bus upside down with most of the roof collapsed. It was reportedly carrying 57 people from the eastern commercial hub of Yiwu in Zhejing province to Xuyong county in Sichuan province, which lies west of Guizhou. The official Xinhua news agency quoted a Guiding county government spokesman as saying an initial investigation had concluded that the bus driver was "fatigued and speeding." The crash was one of several major accidents reported in the last few days as millions of people across China travel home for the traditional lunar new year holiday, or Spring Festival, which begins on January 23. Eight people died and 13 were injured after a bus hit a truck in the south-western province of Yunnan on Wednesday night, while 13 died and 41 were injured in a similar collision in the central province of Hunan on Tuesday. Transport officials have forecast that China's roads will carry some 2.85 billion passengers over the Spring Festival peak travel period from January 8 to February 16.