About 2,000 demonstrators concerned about pollution have taken to the streets in southern China to protest plans for a planned refinery on the outskirts of the city of Kunming.

Government officials said this week that the project by the powerful state company PetroChina will meet environmental standards and is crucial to the local economy. The refinery is expected to produce up to 10 million tons of refined oil annually.

Citizens remain worried that the facility will pollute local air and water. They want the government to make the project's environmental evaluations public.

The Chinese public, especially members of the country's rising middle class, have become more outspoken against environmentally risky plants. Several protests against such projects turned violent last year, in some cases prompting local governments to scrap plans.