A warning has been issued by Llanfair Caereinion Town Council following reports of large numbers of children, some unsupervised, swimming in the river.
Police across the country have been issuing warnings about the dangers of swimming in rivers, lakes and reservoirs which are still perilously cold despite the warmer weather.
The council posted on Facebook: “It has been brought to our attention that children of all ages are swimming in the river. Please be aware of how dangerous this can be. Please make sure all children are supervised at all times."