A week after a deadly high-speed rail crash sparked widespread criticism that China has put its development before public safety, authorities are struggling to contain the anti-government backlash.

The crash was on Sunday the most discussed issue on Sina's hugely popular microblogging site Weibo, where netizens have unleashed a week-long torrent of vitriol, questioning the safety of the fast expanding train network.

And despite signs the government may be clamping down on traditional media, Internet users were still furiously critical of the handling of the accident on July 23 near the eastern city of Wenzhou, in which at least 40 people died.

The government "doesn't have the courage to face up to its mistakes, doesn't have the confidence to accept being called into question, and doesn't know how to live harmoniously with its people," one Internet user said.

State-run newspapers have been unusually outspoken in their coverage of the collision, which left nearly 200 people injured, defying directives earlier in the week that reportedly ordered them not to question the official line.

A comment piece on the front page of the People's Daily, the Communist party mouthpiece, said Thursday that China "needs development, but does not need blood-smeared GDP".

The wide-ranging backlash prompted Premier Wen Jiabao -- who often travels to the scene of a disaster as soon as it happens -- to take a trip to Wenzhou on Thursday, where he promised to punish those responsible for the crash.

In a highly unusual admission by a senior Chinese leader, Wen said he had been unable to come earlier due to illness -- comments that analysts said suggested top leaders had disagreed over how to handle the disaster.

Zhu Dake, a professor at Shanghai's Tongji University, said that despite the public backlash, the government was unlikely to change the way it deals with similar issues in the future.

"I think Premier Wen is a lonely voice (within the Communist Party)... I have absolutely no hope that the government will change its attitude or methods in dealing with big accidents," he said.

Beijing can also count on an army of web censors, who enforce what is known as "The Great Firewall of China" to damp down dissent among the world's largest online population -- estimated to number around 485 million people.

Crackdowns have seen the government block online discussion following this year's popular uprisings in the Arab world and to crush rumours in early July that former president Jiang Zemin had died.

In a sign that censors were clamping down on reports of the train accident, some traditional media that had been vocal about the crash were quiet Sunday.

Hong Kong's Sunday Morning Post said that Chinese propaganda authorities had issued a censorship order late Friday, banning all coverage of the crash "except positive news or information released by the authorities".

The reported clampdown came after the first such directive appeared to have been widely flouted. The Post gave the example of the state-run Beijing News, which reportedly had to scrap nine pages due to the new order.

On Sunday, it ran just two stories on the crash, reporting on relatives who had accepted government compensation for the death of their loved ones, and on a man's quest to find a watch belonging to his wife, a victim of the accident.

The government has struggled to quell similar criticism in the past.

When a devastating earthquake hit the southwestern province of Sichuan in May 2008, authorities initially allowed relatively open coverage of the disaster, which left 87,000 people dead or missing.

But they soon tightened media controls, restricting the movements of journalists in the quake zone amid widely-voiced public suspicion that graft was at the root of the widespread collapse of schools.

Similar online campaigns accompanied the baby milk scandal in 2008, when melamine, an chemical normally used to make plastic, was found to have been added to formula to make it appear higher in protein content.

Six babies died and 300,000 were made ill.

David Bandurski of the University of Hong Kong's China Media Project compared the current situation to the 2003 outbreak of the deadly SARS epidemic.

At the time, state-run press was given a long leash in its reporting of the outbreak, but authorities gradually reasserted control and ended up handing out penalties to 10 different media.

"They waited in the wings until the crowds dispersed -- metaphorically -- and then they went after them individually. That's pretty typical," he said.