Austria's presidential vote is too close to call, pollster groups suggest.
Far-right candidate Norbert Hofer of the Freedom Party (FPOe) and his Green rival, Alexander van der Belle, were each projected to receive about 50 percent, with some 97 percent of the votes counted.
The provisional result from the Interior Ministry gave Hofer a lead with 51.9 percent to van der Bellen's 48.1 percent. The result did not include postal voting.
The final results are due on May 23 once the postal vote is counted.
The migrant crisis was a key issue in the vote.
Austria took in 90,000 asylum seekers last year, more than 1 percent of its population, many of them shortly after it and neighboring Germany threw open their borders last autumn to a wave of migrants including refugees from Syria's civil war.
The government has since clamped down on immigration and asylum, but that about-face only fueled support for the far right.