Alstom, the French engineering group falsely blamed for a metro accident in Shanghai, said Friday that China needed to "absorb and master" the new railway technology it has acquired in recent years.

China has developed its vast at breakneck speed, building the world's largest high-speed rail system from scratch in less than a decade.

But the government has been accused of overlooking safety in its rush to develop, following a high-speed rail crash that killed at least 40 people in July and a metro crash in Shanghai on Tuesday that injured nearly 300.

"The way they acquired and learned the technology in China was very fast. But then you need to absorb and to master," Dominique Pouliquen, president of Alstom , told journalists.

Alstom's Chinese joint venture, CASCO, made the signalling system used on the Shanghai metro line where this week's accident took place, which was initially blamed for the crash.

Authorities later announced that a power cut had knocked out the system entirely and that human error was to blame for the , but not before a series of highly critical articles in China's state-run newspapers and online.

"The impact for us has been tremendous," said Pouliquen of the negative publicity.

He said there were "lessons to be drawn" from the and that the company had received calls from clients in other parts of Asia concerned about their systems.