Mass disturbances are often sparked by plans for the construction of large projects, the committee said.

According to the Guangdong regulations, local governments are required to conduct a survey of the risk to social stability - including an assessment of the likelihood of mass disturbances, the numbers expected to be involved and the scale of possible disturbances - before major policies and reform measures are announced or construction work begins on key projects.

In 2011 alone, 54 key policies and 36 large projects were suspended in Guangdong after being assessed as posing a high risk to social stability, according to sources with the local political and legislative authority.

"Guangdong has taken the lead in the introduction of this sort of assessment mechanism. After all, the province has witnessed a number of mass incidents in the past few years," said Han.

In 2009, plans to build a garbage incinerator in the Panyu district of Guangzhou were dropped after large-scale protests by residents concerned about the possible environmental impact.

Following the NDRC's new rules, several other provinces and municipalities, including the coal-rich province of Shanxi and the megacity of Chongqing, have announced similar rules for local investment projects, said sources with the local governments.

"Regulations such as these are a big step forward. But some confusion remains as to how these social risk assessments should be carried out and which government agency should be responsible for conducting them," said Han.

"In addition to the social risk assessment, local governments should better inform the public about proposed large projects before making a final decision."