More than 20 rail projects across the mainland are using signalling components and control equipment supplied by Casco Signal, the company whose malfunctioning devices were initially implicated in both the deadly Wenzhou high-speed-train crash in July and Tuesday's Shanghai subway collision. The list of projects includes key transport links such as the Beijing Airport Express and the Beijing-to-Shanghai high-speed rail link, and at least a dozen other projects under construction, according to a list published online by Caixin Century magazine. An initial investigation into the Shanghai crash has pointed to a power cut as being the cause of the signalling fault and that the collision was caused by staff failing to follow correct procedures, Shanghai Metro said in a statement last night. Alstom, the French firm that partly owns Casco, denied its products were connected to the Wenzhou crash. 'Casco only provided the apparatus that is inside the station, which consisted of panels to inform passengers of the train departures and arrivals,' an Alstom spokeswoman said of the July 23 disaster. Tuesday's collision, which injured at least 284 people, has provoked a public outcry on the mainland, coming so soon after the accident in Wenzhou, which claimed at least 40 lives and shook confidence in safety standards on the nation's rapidly expanding rail network. Casco signalling equipment on the line malfunctioned just over 40 minutes ahead of the collision, in which one train ran into the rear of another, and trains were being directed manually at the time. Shanghai's city government launched an investigation into the subway accident. Officials declined to comment on whether equipment failure or human error was directly responsible for the collision. A State Council investigation into the Wenzhou high-speed train crash has yet to report on the cause of that incident. Casco is a Shanghai-based joint venture enterprise between China Railway Signal and Communication Corporation and Alstom. It is not the first time the firm's systems have come under fire. It was chastised for a signal circuit malfunction that resulted in a minor collision between two trains on Shanghai's Line One in December 2009. Shanghai's Line 10 - the route on which Tuesday's collision occurred - has been plagued by stoppages and glitches since it opened in April last year. Operations were suspended on a 12-station stretch in the centre of the line for most of yesterday, but services resumed at 8pm, according to the Shanghai Metro website.