Monday, November 15, 1999 Published at 18:32 GMT
Picture gallery: Life in a Nairobi slum
Girls in Mathare play with homemade footballs made from plastic bags and string. Many youngsters dream of playing football professionally as an escape from the poverty.
The children were very excited by having their photos taken. One of them said they had never seen young Kenyans taking photos before - only tourists.
During the rainy season many people lose their homes, but with nowhere else to go they rebuild. Cholera outbreaks are common.
When this boy grows up he wants to be president. He is imitating President Moi by carrying his trademark rungu.
The Mathare Youth Sports Association started as a development project in 1987 to organise sports and community activities. It now runs Africa's largest youth football league with more than 1,000 teams and 14,000 boys and girls.
Children whose parents cannot afford to send them to school often end up working and looking after younger siblings.
This boy says he wants to kill an antelope so that his family can celebrate.
Shootback is published by Booth-Clibborn Editions and costs £25 ($39.95). All royalties from the book's sale goes towards school fees for the Shootback team of photographers and a fund for a Mathare community media centre. Exhibitions are planned in the next few months in Germany, Norway and Holland.