Senegalese presidential election started Sunday at 08:00 local time (08:00 GMT) with 6.68 million registered voters expected to cast their ballots throughout the country and abroad.

Contesting for the presidential seat are incumbent president Macky Sall, former prime minister Idrissa Seck, former foreign minister Madicke Niang, academician Issa Fall, and former tax inspector Ousmane Sonko. Seck is seen by local media as the main challenger to Sall.

A total of 15,397 polling stations are opened to the Senegalese voters at home, and 746 for those overseas.

Across the country, 10,000 policemen are deployed to ensure security, with about 5,000 observers from the European Union, the African Union, the Economic Community of West African States, and local civil society organizations.

In 2012, Sall won the second round of the presidential election over then president Abdoulaye Wade, becoming the fourth Senegalese president since independence.

If no candidate can obtain over 50 percent of the vote during the first round, a second round will be held with the top two candidates.

According to officials, polling stations are scheduled to close at 18:00 local time (18:00 GMT), but voters will be allowed to vote if waiting time exceeds the closing time.

This year's presidential winner will start a reduced term of five years, after a 2016 referendum that cut the presidential term from seven years. 

Xinhua