Two teenage boys have drowned in the Swan River after a foot chase with police in Perth's inner-city suburb of Maylands on Monday afternoon.

About 3.15pm on Monday police responded to reports of five teenage boys jumping fences near Tranby and Clarkson Roads in Maylands.

It's understood they had trespassed on the Maylands Bowling Club before police were called and when officers arrived the boys fled on foot.

After the officers gave chase, some of the boys ran into the Swan River near Tranby Road to evade capture.