Fourteen people have pleaded guilty to charges of “inciting violence” during a protest in the eastern Chinese city of Qidong, state media have said.

The protest, in which thousands of people clashed with police after storming government offices over a proposed waste water pipeline last year, was one of a series of environmental protests in China, according to AFP.

Local residents said the project would pollute coastal waters. It was eventually scrapped.

The 14 defendants were tried on Wednesday for their violent behaviour which “caused property losses, injured police officers and severely disrupted public order,” prosecutors said.

Demonstrations against environmental degradation have gained momentum in China amid increasing public awareness on the repercussions brought by rapid and unfettered industrial expansion.

“Off-the-scale” smog plunged Beijing into a thick haze on Tuesday, forcing airlines to cancel flights as visibility dropped and prompting calls for the government to report more openly on air quality problems.