Child marriage will cost African countries tens of billions of dollars in lost earnings, the World Bank has said.

It published a report for the African Union Commission’s summit on ending the practice that is taking place in Ghana this week.

The World Bank says young brides are more likely to drop out of school, meaning they are likely to earn less money.

On average, women who have a secondary education are more likely to work and they earn twice as much as those with no education, the report says.

Estimates for 12 nations, accounting for half of the African continent’s population, suggest that through its impact on girls’ education, child marriage is costing these countries $63bn (£49bn), it added.

Quentin Wodon, principal author of the report, said:

Primary education for girls is simply not sufficient. Girls reap the biggest benefits of education when they are able to complete secondary school, but we know that girls very often don’t stay in school if they marry early."