Voters in Togo are going to the polls to choose a new president in an election that could see incumbent Faure Gnassingbe win power for a third five-year term.

Polling stations in the tiny West African nation opened at 0700 GMT on Saturday for some 3.5 million of the country’s seven million people who have registered to vote.

Some 9,000 police and military forces, who have already cast their ballots, are providing security. About 500 international observers are also reportedly overseeing the voting at more than 4,000 polling stations.

The Togolese government announced that land borders have been closed from 2100 GMT on Friday until 0600 GMT on Sunday "to ensure optimal security conditions" for the elections.

Gnassingbe, who won contested elections in 2005 and 2010, is the favorite in Saturday's voting but he is faced with a challenge from main opposition leader Jean-Pierre Fabre.

The incumbent president’s win in the election will extend his family's grip on power into a second half-century.

Gnassingbe, 48, has been in power since the death of his father, Gnassingbe Eyadema, in 2005.

On the campaign trail, Gnassingbe promised free primary schools and infrastructure projects such as new roads.

Fabre, who heads a five-party coalition called Combat for Political Change (CAP 2015), has called for regime change after 48 years of uninterrupted rule by the president and his father.

On the eve of the presidential election, United Nations Secretary-General Ban Ki-moon called on all national stakeholders on Friday to recommit themselves to ensuring that the election is conducted in a peaceful, free and transparent manner and reflects the will of the Togolese people.

There are no term limits currently in the West African nation. Last year lawmakers in Togo considered a bill that would reintroduce term limits, but it did not pass.