Residents of Argentina's capital have gone to the polls in mayoral elections widely viewed as a test of President Cristina Fernandez de Kirchner's re-election hopes.

Buenos Aires' incumbent mayor, Mauricio Macri, is expected to win Sunday's vote, but fall short of the majority needed to avoid a July 31 runoff. The businessman and former head of a football club is running against government candidate Daniel Filmus, who was hand-picked by President Fernandez. Filmus is a former education minister.

The capital's 2.4 million voters represent nearly 10 percent of the country's voting population. Analysts are watching Sunday's vote as a gauge of the president's popularity.

Analysts, however, say a defeat for Ms. Fernandez's candidate in Buenos Aires will not hurt her chances of winning re-election October 23. Under Argentina's electoral system, candidates can win the presidency in the first round with 40 percent of the vote as long as their nearest rival trails by at least 10 percent.

A candidate who gets more than 45 percent of the vote wins the presidential election outright.