The UN has projected that Nigeria's population will reach up to 189 million by 2050.
The UN Department of Economic and Social Affairs (DESA) in an earlier report said Nigeria, which currently ranks seventh, would be the third most populous country by 2050 and likely to replace the U.S.
The World Health Organisation will convene an Emergency Committee on Friday to consider the international risks of an Ebola outbreak in the Democratic Republic of Congo, WHO said.
The expert committee will decide whether to declare a "public health emergency of international concern, which would trigger more international involvement, mobilising research and resources.
Congo's health minister, Oly Ilunga, said that the outbreak was entering an urban phase and had spread to the capital of Equateur province in the northwest.
23 deaths have, so far, been reported among the 42 suspected, probable and confirmed cases of the disease.
Burundians are voting in a contentious referendum on term limits that could see the country's recently declared 'Supreme Eternal Leader' Pierre Nkurunziza stay in power until 2034.
Ahead of the referendum, the government banned three international broadcasters, including the BBC, and many local opponents of the referendum have either been arrested or have fled abroad.
Rights groups, as well as the U.S. State Department, have denounced an atmosphere of intimidation in the lead-up to the vote and the country's divided opposition has called for people to vote "No" or boycott.
China's first privately built rocket had a test launch on Thursday, the latest step in the country's push to open its space programme to private companies.
Beijing-based start-up OneSpace said its 9-metre-long carrier rocket, Chongqing Liangjiang Star, blasted off from a base in north-west China.
The rocket, weighing 7,200 kilogrammes, reached five times the speed of sound and travelled a distance of 273 km.
A study, journal Fertility and Sterility, has revealed that depression in men was largely responsible for lower pregnancy chances among couples looking to making babies.
The study also linked a class of antidepressants to a higher risk of early pregnancy loss among females being treated for infertility but neither depression in the female partner nor use of any other class of antidepressant were linked to lower pregnancy rates.
Sri Lanka's health officials on Thursday warned that a new virus affecting children was spreading in the island's south as five deaths had already been reported.
The symptoms of the disease include high fever, cough and breathing difficulties and affects children less than two years old.
According to Dr Aruna De Silva of the Paediatric Unit at Karapitiya Hospital, the disease is associated with a virus which causes Pneumonia.