Following a tailings spill from the Catoca diamond mine in Angola in July, 12 people died and 4,400 people were ill in the southern Democratic Republic of Congo, according to Congo’s environment ministry.

Following a visit to Kasai province, where the Tshikapa river turned crimson and many fish perished, Environment Minister Eve Bazaiba said Congo will seek compensation for the damage, but she couldn’t specify how much. a

Congo will seek compensation based on the “polluter pays” principle, according to Bazaiba. She didn’t go into detail about how the 12 individuals perished.

Kasai provincial governor Dieudonné Pieme banned people from drinking water and eating fish from the Tshikapa river after the spill, which he said significantly depleted the river’s fish population.

Sociedade Mineira de Catoca, which manages the mine that produces 75% of Angola’s diamonds, did not immediately respond to a request for comment on the deaths.

The company previously said it immediately took measures to minimize the flow of sediment into rivers and that it donated food baskets to affected communities to mitigate the impact of the spill.