'I was an al-Shabab recruit'
Kenya's President Uhuru Kenyatta says his country is at war with the Somali militant Islamist group al-Shabab.
Thousands of Kenyan troops are part of the African Union force fighting al-Shabab in Somalia.
But some analysts estimate that nearly a quarter of the group's fighters are Kenyans who it recruits in the country's poverty-ridden slums.
The BBC's Tom Burridge met one young man who said he was recruited by al-Shabab when he was 18.
He said he spent two years in Somalia and had now left the group and was back in Nairobi.