A global industry group says Africa is the fastest growing mobile phone market in the world.

In a report released Wednesday, the Groupe Speciale Mobile Association said the continent is also the world's second largest mobile market by connections, after Asia.

The GSMA said Africa outpaced all other mobile phone markets in a three-month period of this year, when it reached 649-million connections.

The report said the number of mobile phone users in Africa has increased by nearly 20 percent every year for the last five years. And it predicted the robust growth to continue.

Still, the industry association reported a “huge untapped potential” in Africa, saying more than a third of Africans in top markets still do not have access to mobile phones.

The organization called on countries to invest in infrastructure to help expand service, especially to rural areas where there is none at all.

The association represents mobile operators and related businesses in more than 220 countries.

Its report says Nigeria has the highest number of mobile phone subscriptions in Africa, with more than 93 million mobile phone users.

South Africa, which has a more developed infrastructure, topped the continent in terms mobile broadband penetration.

The group singled out Kenya as the leader of mobile money transfers and what's termed “m-banking.” It said 8.5 million users in Kenya use mobile devices to help manage their finances.