Dead pigs are seen drifting after a farm flooded by heavy rainstorms in Liuye Township in Southwest China's Guangxi Zhuang Autonomous Region on June 16. [Photo/Xinhua]

Though the pigs died from natural disasters, limiting the risks of spreading epidemics, Nong cautioned that carcasses can rot faster at high temperature and will pollute rivers and cause infectious disease if not immediately cleaned up.

Heavy rains have lashed much of south China over the past few weeks, causing floods and landslides, bringing down buildings and killing crops in the region. The latest rainstorms in the autonomous region have killed eight people so far and left three others missing, local authorities said Tuesday

In March 2013, thousands of dead pigs were seen drifting in Shanghai's Huangpu River at the lower reaches of the Yangtze River, causing public concern over the contamination of water sources for the city.