Part of a high-speed railway line that had undergone test runs has collapsed in central China after heavy rain, reviving worries over safety.
The official Xinhua News Agency said a 300-metre section of the line had collapsed, but mentioned no casualties or other details. Hundreds of workers were rushing to repair the line between the Yangtze River cities of Wuhan and Yichang.
The reports of the accident on Friday near Qianjiang city in Hubei province, the latest since a bullet-train crash last summer that killed 40 people, rattled share markets in Hong Kong and Shanghai, where major railway company stocks dropped.
China has 13 high-speed railways in operation, with 26 under construction and 23 more planned. Much of the system, similar to that in Japan, is built on elevated tracks.
Engineers working on some projects have complained of problems with contractors using inferior concrete or inadequate steel support bars.
The state-run magazine Time Weekly has reported allegations that builders on another section of the same Wuhan-Yichang line might have compromised safety by substituting soil for rocks in the railway bed. The line is due to open in May.
China has massive resources and considerable prestige invested in its showcase, high-speed railways programme, and the news appeared to raise sensitivities over the issue. A local government website ran an article denying any collapse had occurred.
Authorities slowed expansion of the multi-billion-dollar bullet train system following the 23 July crash near Wenzhou, in south-eastern China. It was triggered by a lightning strike, though a government probe also blamed faulty signal systems and mistakes by train operators.
Since then, there have been reports of problems with brakes, signalling systems and faulty construction. In one case, the railways ministry ordered almost all of a £165 million line in north-east China to be redone after finding contractors had farmed work out to unqualified construction firms that filled bridges’ foundations with rocks and sand instead of concrete.
A report by experts from the World Bank last week lauded China’s success in rapidly expanding the system, which is due to grow to 10,000 miles of track by 2020 from 3,700 miles last year.
That report said it was unclear whether the speed of the buildup had compromised safety but noted the Wenzhou accident showed there was “room for improvement”.
Huang Qiang, chief researcher with the China Academy of Railway Sciences, said Beijing was continuing a safety overhaul of high-speed railways that included development and improvement of signalling equipment, train maintenance and protection against lightning and earthquakes.
“China’s high-speed railway development has been aggressive in previous years, in which some important links were missed,” Xinhua quoted Mr Huang as saying.