Is the furious online backlash against the Chinese authorities, sparked by a high-speed rail tragedy in which 39 people died, China's "Tiananmen 2.0"? Channel 4 News investigates.

Censorship in China is being undermined by microblogging sites, as the Wengzhou crash shows (Getty)

China is in mourning after a horrific high speed rail crash in Zhejiang Province on Saturday killed 39 people and left almost 200 injured.

An initially tardy response from the authorities appeared to become considerably more sinister when wreckage from the crash was buried, looking like a cover-up.

But in a country where oppression is the norm, the Chinese people are no longer suffering in silence. People are daring to speak out.

To do this, they are using "weibo", micro-blogging sites like Twitter. Twitter is banned in China but the Chinese versions are popular, and users have posted around 26m messages on the sites about the tragedy.

If they take this channel away, does it spill out onto the streets? Charles Custer, China Geeks

One expert on China and the internet told Channel 4 News this unprecedented openness was "putting the fear of god" into some Chinese officials.

Rebecca MacKinnon, a senior fellow at the New America Foundation in Washington who worked for CNN in China for nine years, said: "These kinds of services are definitely having an impact, and in some ways putting the fear of god into officials because it is much harder to cover things up."

Train wreckage after the Zhejiang Province train crash (Getty)

Crash and 'botched handling'

The clean-up after the Zhejiang Province train crash is a case in point.

When officials buried a train carriage soon after the accident, bloggers and weibo-ers kicked into action, accusing the Government of a cover-up and even posting footage of the burial on the Chinese version of YouTube.

Following this online wave of fury, on Monday, the railway authorities were forced to dig the carriage back up in a bid to prove they had nothing to hide.

Charles Custer of China Geeks, a website which analyses modern China, told Channel 4 News this remained unconvincing.

Speaking from Beijing, he said: "The official line is that they buried the carriage to aid rescue efforts and once they did that, they dug it back up again for investigation. But certainly the more cynical might think there was other inspiration."

Mr Custer told Channel 4 News the apparent u-turns were a sign of the increasing power of weibo in China.

"I think the Government is slowly realising they cannot do things the way they have traditionally done them, and have weibo be the way it is now. The crash was bad enough but the botched handling of it - I think they see they cannot respond slowly and control the media when the news is posted millions of time in an hour."

He said the question was what form the "confrontation" between the Government and weibo would take - and whether it could be shut down.

He said: "They certainly have the power to put an end to it if they want, but it's about whether they are willing to do that. The question is, with all this criticism out there, if they take away this channel, does it spill out onto the streets?"

Social networking sites, known as 'weibo' in China, have had an impact after the train crash (Getty)

Not 'Tiananmen 2.0'

But former CNN China Bureau Chief Rebecca MacKinnon, who is also a co-founder of the international blogging community Global Voices, cautioned against seeing this as "the next step towards Tiananmen 2.0" - partly because the social media sites are still controlled by the state.

She said the Government allows debate to go only so far, before it clamps down. For example, while criticism of individual incidents or officials can go through, this is halted when there is any wider call for political change or democracy.

"For instance people tried to use the same tools to organise protests to echo the revolutions in the Middle East. That failed miserably," she told Channel 4 News.

In fact, the central Government can in a way pander to its population by acting on some of their lesser, local demands - while maintaining its national political grip.

"The situation is the internet enables a lot more public debate without the Government having to change the fundamental political or legal structure. So you could make the argument that this will enable the Communist Party to stay in longer," she said.

She concluded: "One of the things we jump to assume is because local officials are having their heads handed to them as a result of microblogging is that this is the next step towards Tiananmen 2.0. I would caution against making that assumption."

Tributes to China's dead at the train crash site (Getty)