China will start assessing the "social risk" of major projects, its environmental protection minister said Monday, after anti-pollution protests forced a series of industrial ventures to be cancelled.

Chinese are increasingly concerned about how environmental damage resulting from decades of dramatic economic growth may affect their lives.

"The central committee of the party and the State Council have made very clear that from now on all the major projects cannot be launched without social risk evaluations," minister Zhou Shengxian told a press conference.

Separate environmental impact assessments must be posted online and include more community input, under a change which came into force in September, he said.

Zhou attributed recent incidents to growing local concern about environmental hazards but also to faulty approval and evaluation processes.

"We are starting to see a phenomenon called 'Not in my backyard'," he said. "I think it is natural when a society has developed to a certain level."

But trouble also arose when projects were launched without approval, local authorities did not govern adequately and assessments of the environmental and social impact were not conducted properly, he said.

Environmental pollution and perceived health threats have sparked a series of protests, fuelled by social media which lets organisers publicise their causes and rally others despite tight controls in the one-party state.

Late last month thousands of protestors in the eastern city of Ningbo forced authorities to cancel work on a chemical plant, although some residents said they suspect the project might be revived later.

Also in October police clashed with residents for four days in the southern town of Yinggehai over the construction of a coal-fired power station.

Earlier this year hundreds of protesters clashed with police over a planned metals plant in southwestern Shifang city, forcing the project to be scrapped.

Zhou acknowledged that protests had occurred but said that in such a vast country incidents did not necessarily create a trend. "China is such a big country it is so easy to prove one's point," he said.

He spoke at a press conference on the sidelines of a five-yearly Congress of the ruling Communist Party at which it will announce new leaders for the next decade.