Forbes magazine has named Africa's richest man — a Nigerian tycoon who made his fortune in sugar, flour, and cement.

This is the second year in a row that Aliko Dangote has topped the list of Africa's 40 richest people, with a reported net worth of $12 billion.

Forbes says most of Dangote's wealth comes from his cement business, which operates in 14 countries.

Nicky Oppenheimer of South Africa and his family were second on the list with $6.4 billion, followed by another South African, Johann Rupert, who along with his family has $5.7 billion.

Only two women are on the list of Africa's 40 richest. One of them is entrepreneur and investor Isabel dos Santos, daughter of the Angolan president.

The list includes only Africans who live on the continent.