Austria's populist, right-of-center Freedom Party has doubled its share of the vote in a regional election amid concern about the influx of refugees in recent months.

Preliminary results put the Freedom Party in second place, with 30.9 percent of the vote in Sunday's Upper Austria election — compared with the 15.4 percent it received in 2009.

The party's gain contrasts with a 6-percent loss for the center-left Social Democrats and an 11-percent loss for the center-right People's Party, which remained in first place with 37.4 percent of the vote.

Exit polls published by broadcaster ORF showed almost two-thirds of voters placed a heavy emphasis on the issue of refugees.

Austria has become a transit country for tens of thousands of people hoping to start a new life in Europe.