KIGALI, Rwanda

Health officials in the Democratic Republic of the Congo have recorded thousands of diarrhea cases in central Kasai province after residents consumed contaminated water and dead fish from polluted river, an official said Tuesday.

The humanitarian crisis has been reported after a diamond mining complex in Angola has reportedly emitted toxic substances since July, which have polluted the Democratic Republic of Congo's Kasai and Tshikapa rivers that flow from Angola.

“More than 4,000 cases of diarrhea were registered in 13 of the 18 health zones affected in Kasai region,” Eve Bazaiba, deputy prime minister in charge of the environment, told journalists following her assessment of the situation in the area.

The polluted tributaries feed into the Kasai River, west of the Central African country.

Local officials in the Kasai region have reported that the river turned colored and dead bodies of hippos and fish were found in the polluted waters.

Bazaiba said residents have been warned against consuming dead fish.

There are fears Congo River, the second longest African river after the Nile, could also be polluted as Kasai feeds into it.

Congolese researchers in Kinshasa have warned that water pollution could have negative effects for several years.

Some residents have also reported contracting skin rashes after using the polluted water, according to local officials.

Bazaiba assured that the government had taken steps to increase safe water supply to the affected areas.

Noting that efforts are underway to engage Angolan officials over the matter, the official said it was yet to be established whether the emission was by mistake.