Net enrolment in primary school in sub-Saharan Africa has risen to 76% in 2010 from 58% in 1999, according to UNESCO's 2012 'Education for All' survey.
The gross enrolment ratio for junior-secondary schools remains under 60% in 19 sub-Saharan African countries.
School authorities struggle to find classroom space, and there is also a shortage of trained teachers for secondary-school classes.
In Ghana, the presidential candidate for the opposition New Patriotic Party, Nana Akufo-Addo, promised to offer free universal senior-secondary school education in September 2013.
Experts questioned his estimated ¢78m ($41.5m) costings.
Secondary education is already free in Kenya and Uganda.
In 2009, Rwanda started to offer free junior-secondary education, which boosted enrolment by 27%.
This put pressure on teaching quality despite the building of more than 3,000 new classrooms●