Syria, Russia and Afghanistan have the largest numbers of people fleeing their homelands to seek asylum, and most are turning to Europe, the United Nations refugee agency said in a report Friday.

Syria's 3-year-old civil war generated 56,351 asylum seekers in 2013, more than double the previous year's total of 25,232, according to the Office of the United Nations High Commissioner for Refugees. Syria became the world's biggest source for asylum seekers, surpassing Afghanistan, which fell to third.

Russia, meanwhile, become the second-biggest source of asylum seekers with 39,779, up from 22,650 in 2012.

Volker Turk, the agency's director of international protection, attributed Russia's surge to rising unrest in the Russian region of Chechnya. He forecast that Syria's refugee problem would worsen this year.

The U.N. report found that 38,653 Afghans sought asylum last year, versus 47,519 in 2012. It said 38,171 Iraqis and 34,660 Serbians sought asylum in 2013 for fourth and fifth place, respectively.

The 38 nations of Europe experienced the biggest 2013 increase in asylum applications, with Germany, France and Sweden the most popular destinations, particularly for Syrians.

Europe as a whole had 484,600 asylum claims, 32 percent higher than in 2012. Germany received 109,580, France 60,100, Sweden 54,360, Turkey 44,810, Britain 29,190, Italy 27,830, Switzerland 19,440 and Hungary 18,570.

Outside Europe, the United States dealt with 88,360 asylum applications, Australia 24,320.

The report offered few specifics on countries' rates of acceptance of asylum claims. It noted that applicants were more likely to receive favorable treatment if their homelands were suffering active warfare.

It found that most asylum applicants from Syria, Iraq, Somalia and Afghanistan were successful, whereas only 28 percent of Russians and just 5 percent of Serbs won their asylum bids.