What is the social setting in petals of blood by Ngugi wa thiongo?

The novel is set in post-independence Kenya; At the beginning of the novel, Munira, Karega, Abdulla, and Wanja are questioned about the triple murder of three notable Kenyan businessmen, Kimeria, Mzigo, and Chui. As they answer the authorities’ questions, the novel is told primarily in flashbacks going back twelve years to when these four characters first came to the village of Ilmorog (it is set in the post-independence period [1963-], though some of the characters’ memories and stories go back further).