Dar-es-Salaam, Aug 25 - Africa's population has reached one billion as it continues to grow by about 24 million a year, according to a report.

The report published by the Washington-based Population Reference Bureau, jointly with the US government aid agency USAID, says it is expected that the African population will double to nearly 2 billion by 2050, Buanews reported.

Although population growth has slowed in North African countries such as Egypt and Tunisia, on average women in sub-Saharan Africa have more children than women elsewhere.

'While globally the average woman has 2.6 children, in sub-Saharan Africa she has 5.3 children (which is down from 6.7 children in around 1950), the world's highest,' the report said.

Worldwide, 62 percent of married women of childbearing age use contraception, but in Africa the figure is 28 percent, according to the report, which also revealed that sub-Saharan Africa has the world's most youthful population, 'and is projected to stay that way for decades.