Beijing (AsiaNews / Agencies) - Urban warfare in Fengwei, near the city of Quanzhou in Fujian, where on the night of 31 August over 10 thousand people clashed for hours with 2 thousand policemen. In a dramatic crescendo, the protesters seized some officials releasing them only yesterday afternoon. The violence erupted after police tried to disperse a peaceful protest against a refinery, accused of polluting the environment.

Police fired into the air twice in warning and then launched tear gas. Demonstrators responded by throwing stones. Dozens were injured, including the Deputy Director of Fengwei and a police officer who has been hospitalized in critical condition.

Local sources accuse the tannery and the oil refinery of discharging harmful and carcinogenic substances into the water used for drinking.

Residents had repeatedly petitioned the authorities, but were consistently ignored, and two weeks ago they led a peaceful protest. Five days ago, protesters tried to sabotage the sewage plant and took two police officers hostage, who were later released.

So far authorities have not issued precise information, not even on the number of wounded, and speak only of ""a small group of people with ulterior motives" of instigating the protests, but fail to elaborate.

The refinery is crucial in development projects in the area. A joint venture formed between the Chinese Sinopec, Exxon Mobil and Saudi Aramco, 3 global leaders in energy, hopes to have a huge complex in Quanzhou ready by 2012. It will include an oil refinery and ethylene, polyethylene and polypropylene manufacturing plants.

The local authorities say the project is part of its plan to make the city China's next big greenfield refinery site and that the 50,000 tonnes of sewage the plant discharges each day met the strictest environmental standards.  But the villagers of Chengping, who can not cross check this information and have complained many deaths from cancer of the stomach and oesophagus in recent years, since the plant opened in 2007. They say untreated substances are discharged into water and the air has a foul smell. They say that in Fujian, one in every three cancer patients is from Quanzhou.

Rapid industrial development of the countryside in recent years has taken place without adequate environmental and health checks creating real "cancer villages" where poisons dumped in rivers, air and land have polluted the environment and provoked an enormous percentage of deaths and illnesses.  The authorities often deny these situations or admit to them far too late.  The population, devoid of protection, are increasingly taking to the streets and clashing with the police, sent to defend the plants. Zhou Sehngxian, Minister for Environmental Protection, recently acknowledged that the mass protests caused by environmental problems have increased by an average of 30% per year.