The World Health Organization (WHO) and United Nations children's agency have urged African governments to promote the safe reopening of schools during the coronavirus pandemic.

They say prolonged closure of schools is harmful to students and want governments to invest in sanitation facilities to prevent the spread of coronavirus in learning institutions.

The two organisations said students are being exposed to poor nutrition, teenage pregnancies and violence during this extended stay-at-home period.

Schools in Africa are a "safe haven" for children, according to the WHO Regional Director Matshidiso Moeti.

"We must not be blind-sided by our efforts to contain Covid-19 and end up with a lost generation. Just as countries are opening businesses safely, we can reopen schools," she said during a virtual press briefing on Thursday.

The long closure of schools poses a risk to the future of children and their communities, according to Unicef Regional Director Mohamed Fall.

Only six African countries have fully opened schools, according to a survey of 39 countries by the WHO and Unicef.

Some countries reopened schools and closed them soon after because of a surge in coronavirus cases.

Others have reopened for final year students to sit for crucial examinations.

Countries like Kenya have completely scrapped the 2020 academic year.