BEIJING, March 31 (Reuters) - Hundreds of protesters in southern China marched against a chemical plant and environmental degradation on Sunday in a demonstration that the Maoming city government called a "grave violation" by criminals causing chaos.
Photos posted on Weibo, China's Twitter-like microblog service, showed hundreds of demonstrators marching along the streets, an overturned car in flames and protesters laying bloodied on the road. Others showed lines of paramilitary police marching in formation.
The images of violence - which could not be independently verified by Reuters - caused an outcry on Chinese social media, although many were later removed from the site by censors.
Residents of Maoming, in Guangdong province, were protesting the production of paraxylene, a chemical used to make fabrics and plastic bottles at a plant run by the local government and state-owned Sinopec Corp, China's biggest refiner.
Some of the online photos show demonstrators carrying signs calling for the chemical plant to "get out of Maoming".
In a statement published on Sunday, the Maoming city government called the demonstration a "grave violation" of the law that "seriously affects the social order".
The city government said on Monday morning that some demonstrators had hurled bottles and rocks after 10:30 pm Sunday evening (1430 GMT), prompting the police to react.
No one was killed, the government said, without noting whether anyone was hurt.
The eastern city of Ningbo suspended a petrochemical project after days of demonstrations in November 2012, and protests forced the suspension of a paraxylene plant in the northeastern city of Dalian the year before. A similar demonstration took place in the southern city of Kunming last year.
Choking smog blankets many Chinese cities, and environmental degradation, the cost of the country's breakneck economic growth, has earned the ire of an increasingly educated and affluent urban class. (Reporting By Megha Rajagopalan; Editing by Tom Hogue)