The plan, unveiled over the weekend, divides natural disasters, public health and environmental crises and threats to social stability into four colour-coded categories and sets different broad responses from local and central authorities to each. 

Local authorities must inform the State Council, China's cabinet, of "important social security incidents" within four
hours, the rules posted on the central government's website state.

The China Daily said on Monday: "The guidelines come at a time when a string of serious cases, including contamination of drinking water, bird flu outbreaks and mine accidents, have stricken China over the past few months."

Rising rural unrest 

But Beijing is also grappling with an acknowledged rise in rural unrest. 

In August, Zhou Yongkang, the police minister, said there had been 74,000 public protests across China in 2004, and senior police officials and Chinese rights activists have predicted more "mass incidents" around the nation this year.

Much of China's unrest involves farmers angry about official corruption and land-grabs without proper compensation.

"The guidelines come at a time when a string of serious cases, including contamination of drinking water, bird flu outbreaks and mine accidents, have stricken China over the past few months"

China Daily

The guidelines call for local authorities to inform the public of emergencies and "social safety incidents" as soon as possible. They also repeat warnings that officials who delay, cover up or falsify reports will be punished. 

Although more and more natural and man-made disasters are making the Chinese news, domestic media are required to stay tight-lipped about public demonstrations. 

National and local officials have been silent about a bloody crackdown last month on protests over a government land-grab in southern Guangdong province in which armed police opened fire on demonstrators, killing at least three. 

The official Xinhua news agency issued a report a week after the Guangdong incident, blaming "criminals" among the demonstrators for sparking the violence.

Local officials in northeast Jilin province failed to report a toxic spill in the Songhua River in November, which left Harbin, a city of nine million in Heilongjiang province, scrambling to shut off public water supplies for five days. 

The chief of the State Environmental Protection Administration resigned after the incident. 

China was widely criticised in 2003 for its initial cover-up of the Severe Acute Respiratory Syndrome virus, contributing to its eventual spread to 8000 people around the world.