Chinese authorities are dumping chemicals into a river to try to neutralize toxic pollution that threatens water supplies to several southern cities.

The official Xinhua News Agency reported Saturday government workers were pouring iron and aluminum chemicals into the Bei River, near the city of Yingde, in Guangdong province.

The river was contaminated with large amounts of cadmium that leaked from a smelter earlier this month. Officials hope the additional chemicals will force the cadmium to sink to the riverbed, instead of flowing downstream.

Local media said the manager of the smelting factory in Shaoguan city was removed from his post by the government as officials investigate the accident.

Authorities stopped most of the slick by closing a dam on the Bei River. But small amounts of polluted water are still flowing south towards the densely populated city of Guangzhou.