Syrians fleeing the bloodletting at home and a fast-growing web of other crises across the world accounted for the spike in the displaced, the UNHCR said in its annual Global Trends Report.
At the end of last year, 51.2 million people had been forced from their homes worldwide, the highest figure of displacement since World War II, said the UNHCR.
That's six million more people than at the end of the previous year, reflecting what the agency described as important undercurrents in international relations. At the end of 2012, there were 45.2 million displaced in the world, according to the agency.
"The world has shown a limited capacity to prevent conflicts and to find a timely solution for them," said U.N. High Commissioner Antonio Gutteres.
"Today, we not only have an absence of a global governance system, but we have sort of an unclear sense of power in the world," Gutteres told reporters in the Lebanese capital of Beirut, where the global report was launched Friday.
The massive increase was mainly driven by Syria's civil war. By the end of last year, 2.5 million Syrians had become refugees in neighboring countries and more than 6.5 million had been displaced within Syria, the U.N. agency said.
The daunting numbers — which are straining the resources of host countries and aid organizations alike — also are a stark reflection of the ongoing conflicts and persecutions from other countries, including the Central African Republic and South Sudan.
"These numbers represent a quantum leap in forced displacement around the world," Gutteres added. "For the first time since the Second World War, we had in 2013 more than 50 million people displaced by conflict and persecution either crossing borders or within the borders of their countries."
The over-50-million number includes refugees and asylum-seekers who fled abroad as well as people displaced within their own countries. The data was compiled from government, non-government partner organizations and UNHCR's own records.
Of 51.2 million displaced worldwide last year, 16.7 million were refugees outside their countries' borders. Nearly 12 million of them are cared for by U.N. agencies. More than half of the refugees under UNHCR's care — 6.3 million — had been in exile for more than five years, the agency said.
By country, the biggest populations of refugees were Afghans, Syrians and Somalis, the report said. The countries hosting the largest number of refugees were Pakistan, Iran and Lebanon, whose stability is threatened by the raging Syrian war, now in its fourth year.
More than a million Syrians have registered in Lebanon as refugees since the conflict in their country started in March 2011. The refugees now make nearly one of fourth of Lebanon's 4.5 million population.
Heilprin reported from Geneva.
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