Zambia has ordered its largest copper mine to halt a key part of production after a spill polluted local water supplies for thousands of residents.
The town of Chingola is without running water
Konkola Copper Mines was told to shut its leaching plant after it contaminated a river providing water to more than 50,000 people in Chingola.
The town is without running water after local companies say they cut supplies because it was too dangerous to drink.
Pollution was already a concern because of problems in another town, Kabwe.
There, environmental activists say children have faced a threat from pollution caused by the lead mine, which was shut down in the 1990s.
From the time the mine opened in 1902 until its closure, there were few pollution controls and as a consequence Kabwe's vegetation, soil and water are heavily contaminated with the highly poisonous metal, lead.
The government has promised an investigation into the incident at the leaching plant, which is where the final step of purifying copper takes place.
"The water is totally polluted. The levels of pollution are difficult to believe," Chingola town clerk Charles Sambondo said.
Residents first noticed problems when fish started dying in the river.
Then the water turned a thick blue colour, and gave off an unusual odour.
Water companies turned off their pumps earlier this week and there is no running water in the town.
The BBC's Musinda Chibamba says residents are walking around with buckets and bowls on their heads trying to fill them up with water.