The authorities in Uganda are investigating the large-scale death of fish on Lake Victoria, the continent’s largest fresh water lake.
The fisheries ministry has warned the public not to eat the dead fish and to bury them.
It is not clear yet what quantities have washed up on the shores. But photos shared on social media by people living around the lake show dozens of lifeless fish washed up ashore.
The Nile perch, a species of fish that can grow to weigh more than 100kg which is a staple in many Ugandan households, is the most affected.
A statement from the National Environment Management Authority says that the deaths may be caused by a drop in oxygen levels.
The species is said to be sensitive to oxygen levels below two milligrams per litre of water.
Further investigations are being carried out, according to the authorities.
The lake is a vital resource shared between Uganda, Kenya and Tanzania.