Rick Prior, Chair of the Metropolitan Police Federation, said: "The thoughts of all police officers in London are with the family of the 14 year old boy who was killed today, and all those injured.
"This horrific incident is a sad reminder of the incredible bravery our officers display and the dangers they face to keep the public in London safe, day in and day out.
"It's often forgotten by people who attack our profession and the difficult and dynamic decisions which officers are confronted with on an hourly basis, that we work with heroes whose courage is incredible.
"We shall be supporting our injured colleagues, the officers they work with and their families as best we can at this very difficult time."