The new projection predicts a global population around 2 billion lower than some previous estimates.
The attacks,in the Monguno and Nganzai local government areas,came just days after militants killed at least 69 people in a raid on a village in a third area,Gubio.
Sources said gunmen attacked because they suspected residents of sharing information on the terror group's movements with security authorities.
Police said some of the gunmen wielded AK 47 guns in the attacks on villagers.
A cargo flight containing more than 6 million medical items arrived on Sunday in Ethiopia's capital.
The explosion in the Amuwo Odofin area of Lagos destroyed more than 50 buildings,which either collapsed or caught fire,in three different neighbourhoods.
Hundreds of people have been killed in the north-west of Nigeria since last year,in attacks the government attributes to'bandits'.
Most citizens of Nigeria - Africa's most populous nation and biggest economy - and Eritrea would be blocked from coming to live and work in the United States under the measure.
Visible marks on the boys'bodies showed that some had been tortured,police said,as shocked authorities tried to track down their families.
Attacks on foreigners have become common in South Africa. Now pop stars,businesses and sporting bodies from neighbouring countries have had enough.
Facebook impostors have been tracked down all the way to their homes in Nigeria.