The United Nations refugee agency says 800,000 people around the world became refugees last year, the highest number recorded so far this century.

The agency's “Global Trends 2011” report, released Monday, says an additional 3.5 million were forcibly displaced within their countries.

It says most of the displacement stemmed from humanitarian crises in Africa, starting with Ivory Coast in late 2010 and followed by Libya, Somalia and Sudan.

U.N. High Commissioner for Refugees Antonio Guterres said his agency is grateful the international system for protecting refugees and the displaced “held firm,” in his words, and that borders stayed open.

The U.N. says a total of 42.5 million people ended the year as refugees, displaced or seeking asylum, a slight drop from 2010. The drop was attributed to large numbers of displaced people returning to their homes.

Overall, Afghanistan remains the world's biggest producer of refugees with 2.7 million — followed by Iraq, Somalia, Sudan, and the Democratic Republic of Congo.