The government of the Democratic Republic of Congo believes toxic waste from an Angolan diamond mine has killed 12 people, left 4,500 people sick, and caused diarrhea along the country's river communities, reports Reuters.

The leak turned a tributary of the River Congo red, killing a large number of fish, hippos, and other animals and has affected 2 million people in the region. 

Back in late July, a reservoir filled with toxic material began to spill into the Tshikapa river which is across the border in the Congo. Now, the Congo is faced with an environmental disaster.

Sociedade Mineira de Catoca, the company that manages the mine, produces 75 percent of Angola’s diamonds, the New York Times reported.

The Congo, which shares a border with Angola 1,600-miles long, will seek compensation in line with the "polluter pays" principle, according to Eve Bazaiba, the country's minister of environment and sustainable development. The "polluter principle" says "those who produce pollution should bear the cost of mitigating it."

“It’s a total destruction of ecosystems, especially aquatic biodiversity,” Bazaiba said as she surveyed the damage to the region.

Bazaiba claims there were "tons of dead fish floating on the river... and then the first reflex was to take the fish". Because of the dire situation, the government warned people not to eat the fish and tested samples of the water laboratories of the capital city Kinshasa. When the results came back a week later, water samples contained heavy metals such as nickel and iron and its pH levels were off, the minister said.

“It’s practically acid,” Bazaiba asserted. “It sucks the oxygen out of the water. There’s no life there anymore.”

Last month in a statement, Catoca acknowledged that there had been a “rupture in the pipeline that works as a spillway.” In its findings, the company said that only sand and water were deposited in the river. “The situation recorded did not represent a risk to the population’s lives,” the company said.

One company employee claims that Catoca never used heavy metals described by Bazaiba.“There could not be toxic materials originating from the Catoca mine because the mine does not use such materials,” the employee recalled. “It was a concentration of sand and water, or to be clear, it was mud.”

Authorities in the Congo have banned communities from consuming water from the river and have sent 40 metric tons of medical supplies to the area.