A toxic chemical spill in southern China is spurring sales of bottled water.

Millions of people in southern China were warned not to drink tap water Friday, following a chemical spill at a mining facility dumped dangerous levels of cadmium into the Liujiang River. In some areas, the level of cadmium measured as high as five times the legal limit.

China's state-run media say the spill affected an area that stretched more than 100 kilometers, including Liuzhou City, which is home to 3.7 million people.

China's Xinhua news agency said the spill was first detected about two weeks ago in Hechi City. An official there said it appears industrial waste being stored at the mining facility seeped into the groundwater and then reached the river.

Chinese workers have been trying to dissolve or neutralize the cancer-causing cadmium. Workers at some sites were pouring lime into the river. The lime mixes with cadmium to form large flakes, which can then be filtered out.

Officials in Liuzhou City had promised residents the water supply would be safe by the end of the day Saturday.