African leaders on Friday adopted a convention -- billed as the first of its kind worldwide -- on the protection of the 17 million people on the continent who have fled their homes.

The convention, which is legally binding, requires member states to provide special assistance for displaced people with special needs, including the elderly, and calls for the prevention of forced displacement.

The summit also took into account the effects of climate change as a major cause of human displacement.

"The important thing about this convention is that it applies to conflict and climate as causes of displacement," the United Nations High Commissioner for Refugees Antonio Guterres told reporters after the signing.

UN humanitarian affairs chief John Holmes said 700,000 people in Africa were displaced by climate events last year.

The convention must be ratified by 15 African states to enter into force.

"From the start, international humanitarian law focused on the refugee issue but not so much on the question of displaced. So with this convention it's a case of enriching international law insofar as displaced people in Africa far outnumber refugees," AU Peace and Security Commissioner Ramtane Lamamra said.

Political upheaval, conflicts and natural disasters have left the continent with between 12 and 14 million displaced people, according to the AU.

Including refugees and returnees, the number of Africans who have fled their homes stands at around 17 million.

The International Committee of the Red Cross (ICRC) lauded the convention as historic, but said it may not have an immediate effect on the plight of the millions of displaced people.

"It is true that the road between ratification and implementation is a long one," ICRC president Jakob Kellenberger told AFP before the convention was adopted. "One can ask how it is going to really improve the protection and assistance of the internally displaced."

"But if on a continental level such an instrument is adopted, it has some value. There is a political and moral engagement on some of the most serious humanitarian issues arising from conflict," he added.

Zambian President Rupiah Banda urged his counterparts to "ensure that we are committed to fostering a political culture of tolerance and good governance as a fundamental mechanism for preventing the internal displacement of our people."

The huge number of those who had fled their homes threatened the continent's stability, AU commission chairman Jean Ping told the summit.

Last year, the 53-member bloc resolved to bolster the protection of refugees and displaced people, but an African diplomat said this week some countries may be reluctant to ratify the treaty because it would be "restrictive and have legal consequences."

However, Kellenberger said the legal provisions are important "because states are obliged to try people who commit international human rights violations, which is in the convention."

Much of Africa's instability has been triggered by political feuds, such as Kenya's unrest after the disputed 2007 elections and Somalia's protracted conflict that erupted after the 1991 ouster of president Mohamed Siad Barre.

Close to a sixth of Somalia's 10 million people is displaced, while Kenya's worst post-independence violence forced some 300,000 from their homes.

Insurgencies in central Africa, northern Uganda and previously in southern Sudan have also displaced millions over the years.

While 46 countries were represented at the summit, only four -- Zambia, Zimbabwe, Somalia and the host country Uganda -- sent their head of state or government.