A campaign to enforce population control measures, including forced abortions, has led to clashes between police and local residents in southwestern China, the New York Times reported. Rioters have smashed and burned government offices in several counties of Guangxi Autonomous Region over the last four days and clashed with riot police in a number of incidents, according to witnesses who spoke on condition of anonymity. Some said as many as five people have been killed. A local government official in one of the counties effected confirmed the rioting but denied reports of deaths or serious injuries. The newspaper said the violence may have been caused by a two-month crackdown to punish people who violated birth control policies.