Greeks also vote for parliamentary elections.

Greeks began voting at precisely 7 a.m. local time (0400 GMT, 12 a.m. EDT) in their most critical — and uncertain — election in decades, with voters set to punish the two main parties that are being held responsible for the country's dire economic straits, says the AP.

Thirty-two parties vie for the votes of nearly 10 million registered voters, many of whom, according to recent polls, were undecided on the eve of the election. Abstention, once projected to reach historic highs but seen rising in recent opinion surveys, will be crucial to the final outcome. In the last national election, in October 2009, just over 70 percent of the registered voters went to the polls, the source reports.