People at Makhuwira Village in Chikwawa on Saturday found dozens of dead fish floating in the Shire River.
The incident has prompted the Department of Fisheries to launch a probe to find out the cause.
Ward Councilor of Makhuwira North Alex Ziggy Mlonya said some villagers used canoes to collect the dead fish. The villagers sold the collected fish in the area.
“We ask authorities to help us as we are not sure on what has killed the fish,” Mlonya told the local media.
Meanwhile, the Department of Fisheries has taken samples of the dead fish to the laboratory to be examined.
The department’s director, Friday Njaya, said people should not eat the fish since they do not know what killed the fish.
“The water flowing in the river is dark while the dead fish are yellowish which makes us suspect of some chemicals,” said Njaya.