Nations Closely Watch Runoff Vote in Mali.

Voters in Mali headed to the ballot boxes Sunday for a presidential runoff, in another step toward re-establishing democracy and rule of law in the West African country.Voting unfolded without major incident, although a second day of rain continued to lash much of the country, flooding parts of the low-slung capital Bamako.

The nation’s Interior Ministry is expected to announce results by Friday.

At stake is whether the election will mend the country’s many divides—or further open them.

Meanwhile, foreign partners—chiefly, France and the U.S.—are counting on an emerging Mali to play a role in their campaign against Islamic militants, which spreads from neighboring Algeria into Nigeria.

With Mali’s government still in disarray, Sunday’s election offered the country’s seven million voters the opportunity to select a head of state whose government would begin shouldering some of the responsibility in the fight against Islamic fundamentalists.

The first-round election in July narrowed the field from 28 candidates, most of whom endorsed former Prime Minister Ibrahim Keita in the two weeks since.

Mr. Keita faced former finance minister and longtime political rival Soumaïla Cissé in a contest to lead a country emerging from twin crises: Mali’s north was conquered by al Qaeda-allied militants last year, while the south was overthrown in a coup.

Since January, French troops have been patrolling the north, and the United Nations recently dispatched a peacekeeping mission there, chasing al Qaeda militants into hiding.

“The important thing here is that the men and women of Mali are getting the chance to express themselves,” Mr. Keita said in an interview in July. “Our social tissue has been ripped to shreds. We have to sew Mali back up.”

In the capital, enthusiasm for the vote, and for Mr. Keita, appeared high. In 2002, the former prime minister lost a bid for president after Mali’s supreme court nullified 34% of the ballots, citing irregularities.

A decade later, Mr. Keita is portraying himself as the forceful opposition leader needed to restore Mali’s honor after the embarrassment of being liberated from al Qaeda by France, the country’s former colonizer.

“For the Honor of Mali,” read some of Mr. Keita’s campaign signs. “Mali First,” read others.

Still, Mr. Cissé retains support from voters and politicians aligned with Mali’s old regime, which was cast aside by last year’s coup.

After Mali’s first-round vote, the candidate and some of his backers accused the electoral commission of fraud. Both Mr. Keita and electoral officials called those accusations false, and Mr. Cissé himself said he didn’t have further details to support his accusations.

But asked in an interview if his supporters might react violently to a victory seen as rigged for Mr. Keita, Mr. Cissé said: “There are risks. Nobody accepts injustice.”

The Wall Street Journal