The piercing chink-chink of two glass bottles being knocked together is what Salma Mukoso uses to announce his arrival at another one of Kinshasa’s crumbling, flaked-paint street corners.

A shy 16-year-old, dressed in flip-flops, shorts and a T-shirt emblazoned with the incongruous word “Police”, he plies the rumbustious streets of the Congolese capital offering the most delicate of services: manicures and pedicures.