Hundreds of demonstrators have gathered in Shanghai to protest against plans to open a lithium battery factory in the city. There is growing social tension over high levels of pollution in China. Police kept a close eye on protesters as they marched peacefully along the city's streets. Protests by residents have been growing in recent months. A mobilisation by residents in the city of Kunming against the opening of a chemical refinery forced the mayor of the city to declare that if the majority of residents were against it, he would not permit the project to go ahead. More about: China, Pollution, Protest