George Paul witnessed the arrest of one of the suspects in Westborne Grove and told ITV News he saw "three policemen holding down one individual - I don't know what ethnic origin he was but he was shouting.
"It was all over in ten minutes."
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The officer fired after the boy, who is being treated in hospital, failed to raise his hands when told to.
A pair of cyclists made the shocking discovery of a baby at the bottom of a drain in Australia.
A weather warning is in place across the south-east with heavy rainfall expected. Elsewhere there will be plenty of sunshine around.