President Ibrahim Keita faces former finance minister Soumaila Cisse who finished second in July’s first round.

Malians voted in a crucial election runoff on Sunday that has been marred by allegations of fraud and a tense security situation in the vast West African country.

It is holding a second election after the 24 candidates who competed for the top seat failed to get more than the required 50 percent of votes in the first round last month.

Voting goes from 08:00 GMT to 18:00 GMT. Turnout was low in the first round at about 40 percent.

President Ibrahim Boubacar Keita, who won 41 percent of the vote in July’s poll, is favoured to beat Soumaila Cisse, who garnered 18 percent, even though violence has surged during his tenure.

AFP news agency reported the head of a polling station was shot dead on Sunday afternoon by armed group fighters in the restive northern Timbuktu region of the country.

The chaotic first round of the vote was a reminder that fighters – some linked to al-Qaeda and Islamic State of Iraq and the Levant (ISIL) – have regrouped since a French intervention in 2013, and are now expanding their influence across Mali’s desert north and into the fertile centre.

‘Return of peace’

Dramane Camara, 31, was the first to vote at one polling station in a school in the capital, Bamako.

“I voted without problem, I came to fulfill my duty as a citizen,” Camara said. “I expect the new president to solve the problem of the north, which is peace. Because the return of peace means the return of NGOs, investors, so creating jobs.”

Sunday’s vote is a rerun of a 2013 face-off that Keita won by a landslide over Mali’s former finance minister Cisse.

It is the first time in Mali’s history that an incumbent president has had to face a runoff. More than nine million people registered to take part in the election.

July’s poll was marred by armed attacks and other security incidents that disrupted about one-fifth of polling places – or 644 stations – and the threat of violence could again dampen turnout on Sunday.

Civil society website Malilink recorded 932 attacks in the first half of 2018, almost double that for all of 2017.

On Saturday, Malian security forces said they arrested three men accused of “plotting targeted attacks” in Bamako.

Fraud allegations

The first round of voting was followed by fraud allegations. Last week, Cisse reportedly mounted a legal challenge in Mali’s constitutional court alleging “ballot box-stuffing”.

On Wednesday, the court said it had registered more than 10 requests from the opposition over anomalies in the first round of voting but that most were declared inadmissible because of timing.

Presidential spokesman Mahamadou Camara denied the fraud allegations.

“All the observers, international and national said that the election was good,” he told Al Jazeera’s Mohammed Vall in Bamako.

“There were some places in the country where people couldn’t vote and the government is trying to change that.

“When the opposition is saying that there was allegation of fraud, it’s because they know that they can’t win this election,” he said.

The head of the EU observer mission said there had been no major incidents at 40 polling stations it had monitored, though no observers were deployed to Timbuktu, Mopti and Kidal, where violence has been rife.

Voting turnout appeared low in the morning, but Camara said this was down to weather conditions.

“It was raining this morning, I think that’s the reason why people didn’t go to vote,” Camara said, adding he thought turnout would see an uptick in the afternoon and evening.

Military deployed

Some armed groups are stoking inter-communal conflict, mostly between herders and pastoralists. Killings along ethnic lines have claimed hundreds of civilian lives this year, including at least 11 last week in the central Mopti region.

Officials in the capital, Bamako, said security will be tightened for the second round, with 20 percent more soldiers on duty.

This means 36,000 Malian troops will be deployed, 6,000 more than two weeks earlier, with a particular focus on Mopti where voting stations had been closed, Cheick Oumar, an aide in the prime minister’s office, told AFP news agency on Saturday.

Outside Mali, the hope is the election winner will strengthen a 2015 accord that the fragile Sahel state sees as its foundation for peace.

The deal brought together government officials, government-allied groups, and former Tuareg rebels.

But a state of emergency heads into its fourth year in November.

Violence has spread from the north to the centre and south of the vast country and spilled into neighbouring Burkina Faso and Niger, often inflaming communal conflicts.