Syrians have overtaken Afghans as the largest refugee population aside from Palestinians, fleeing to more than 100 countries to escape war in their homeland, the United Nations said on Wednesday.

At more than 3 million as of mid-2014, Syrians accounted for nearly one in four of the 13 million refugees worldwide being assisted by the UN refugee agency, the highest figure since 1996, it said in a report. Some 5 million Palestinians refugees are cared for by a separate agency, UNRWA.

"As long as the international community continues to fail to find political solutions to existing conflicts and to prevent new ones from starting, we will continue to have to deal with the dramatic humanitarian consequences," UN High Commissioner for Refugees Antonio Guterres said in a statement.

At least 200,000 people have died and half the Syrian population has been displaced since the conflict began in March 2011 with protests that spiralled into civil war.

Worldwide, an estimated 5.5 million people were forcibly uprooted during the first six months of last year, 1.4 million of them fleeing abroad, the UNHCR said.

The Middle East and North Africa has become the main region of origin of refugees, overtaking the Asia and Pacific region that held the top spot for more than a decade.

Afghan refugees, the biggest group for three decades, have fallen to second place, with 2.6 million hosted by Pakistan and Iran at mid-year, it said. Somalis ranked as the third largest refugee group at 1.1 million.

Syria's neighbours -- Lebanon, Iraq, Jordan and Turkey -- continue to bear the brunt of the crisis.

"With 257 refugees per 1,000 inhabitants, Lebanon remains the country with the highest refugee density at mid-2014," UNHCR said, noting that Jordan ranked second.

Sweden, with 12 refugees per 1,000 inhabitants, is the only industrialised country among major hosts, ranking 10th, it said.

Syrians also formed the largest group of asylum-seekers worldwide during the first half of 2014, lodging 59,600 applications, it said. Germany and Sweden together received 40 percent of these claims, it added.

Iraqis fleeing conflict were the second largest group of asylum-seekers during the period, at 28,900, the report said.

Last year nearly 3,500 migrants perished while trying to cross the Mediterranean to reach Europe, the UNHCR says.