An 11 year-old and a 15 year-old boy were pulled to safety last night.
Both boys were taken to hospital by London Ambulance Service.
One further adult man exited the water before the Brigade arrived and declined medical treatment.
It’s unclear how the pair came to be in the water.
A London Fire Brigade spokesperson said: “The best thing you can do if you see someone in difficulty in the water is to call 999, try to give an exact location about where you are and keep your eyes on the last spot you saw them.
“If you go into the water to rescue people, pets or belongings, you could be putting yourself at risk as well.”
