On February 12, tens of thousands of protestors gathered in Zhenjiang City, Jiangsu Province. They were protesting because the local water supply had been polluted with the chemical benzene.
Police clashed with the protestors, but one day later the local police station denied that the protest had happened.
Residents say they were alerted to the problem when the water coming out of their taps started to have a bleach-like taste.
At first officials said the water company had simply added more chlorine to the water. But after several days, they admitted that the local water supply had been contaminated with benzene.
Officials are now saying the water is back to normal, but local residents are not convinced.