Police should "carry out in-depth investigations" and "enhance people's sense of safety and satisfaction" during the campaign, which was launched by the public security ministry on Friday, Zhou Yongkang said in a statement. "Public security organs at all levels... should promote... the spirit of serving the people, justice, and honesty and do the best to safeguard national security, social harmony and stability," said Zhou, who is a member of the politburo, in the statement published Saturday. The announcement highlights the growing concern in the top ranks of the Communist party over rising social tensions across China as it prepares for a generational leadership handover next year. It comes as thousands of villagers in southern China stage a revolt against local Communist officials. The villagers say the officials have been stealing their land for years and are responsible for the death of a community leader. The 13,000 residents of Wukan, in the wealthy province of Guangdong, have taken to the streets to demand their land back and for officials to return the body of Xue Jinbo, who died in police custody last Sunday. Wukan is located in China's manufacturing heartland where thousands of factory workers have gone on strike in recent months as slowing export demand forces manufacturers to cut pay. In November, more than 7,000 workers went on strike at a Guangdong factory making Western brand shoes, clashing with police in a protest over layoffs and wage cuts. A mass protest earlier this year in the northeastern city of Dalian forced the government to move an unpopular chemical plant -- another sign, analysts say, that China's growing middle class is increasingly willing to fight back.