SAN JOSE, Feb. 1 (Xinhua) -- Costa Ricans head to the polls on Sunday in presidential elections, as more than 7,000 polling stations opened nationwide.

Polls opened at 6 a.m. local time (1200 GMT) and will close at 6 p.m. (0000 GMT). About 3.7 million registered voters are eligible to cast ballots, including over 67,000 Costa Ricans registered to vote abroad.

Voters are choosing from 20 presidential candidates. Laura Fernandez of the ruling Sovereign People's Party has led the race throughout the campaign, with the latest University of Costa Rica survey putting her at 44 percent support. She is followed by Alvaro Ramos of the National Liberation Party at 9 percent and former first lady Claudia Dobles of the Citizen Agenda Coalition at 8 percent.

A candidate needs at least 40 percent of valid votes to win outright. If no one reaches that threshold, the top two finishers will face a runoff in April.

Voters will also elect two vice presidents and nearly 60 lawmakers.