Photo: Sophie van Leeuwen/RNW

Wade supporters in Pikine (file photo).

Senegalese are at the polls to select a leader in a tightly contested presidential runoff election.

President Abdoulaye Wade faces stiff competition from opposition leader, Macky Sall, as the incumbent tries to win a controversial third mandate.

The days leading up to the vote were calm, however many worry that disputes over results could reignite street protests and could threaten the stability of one of Africa's most celebrated and peaceful democracies.

The incumbent, Abdoulaye Wade, is seeking a third term, despite a constitutional two-term limit passed after he first took office in 2000.

The Constitutional Court ruled that he could run in late January, sparking riots that killed at least six people ahead of the first round poll on February 25.

Wade fell short of a majority in the February 26 vote with 34.8 percent.

Sall came second with 26.6 percent. The first-round candidates have now united behind Sall as has civil society group M-23, which has been calling on Wade, 85, to step down.

Both candidates say they are confident of victory. The electoral commission has called on them to abstain from premature declarations of results in the interest of preserving calm.