BAMAKO (Reuters) - In the five years since Malians last chose a president, they have suffered violence from Islamist militants, Tuareg separatists, drug traffickers, ethnic vigilantes and Malian security forces.

Supporters of Ibrahim Boubacar Keita, President of Mali and candidate for Rally for Mali party (RPM) attend a rally in Bamako, Mali July 27, 2018. REUTERS/Luc Gnago

Yet when it comes to elections, power has tended to be contested peacefully in the West African republic, and diplomatic pressure is aimed at keeping to keep it that way when its citizens go to the polls on Sunday to decide whether to give President Ibrahim Boubacar Keita a second term or hand the top job to one of his rivals.

“Mali has demonstrated the capacity over the years to deliver credible and peaceful elections,” Mohamed Ibn Chambas, United Nations Special Representative to West Africa and the Sahel region, told Reuters at his office in the Senegalese capital, Dakar.

“My plea is that candidates again show high responsibility,” he added. “We cannot afford a political crisis in Mali on top of the security crisis the country is already facing.”

Eight million people are registered to vote, with polls opening at 8 a.m. (4.00 a.m. ET) and closing at six (1800 GMT).

Keita, 73, universally known as IBK, runs for re-election amid a mounting death toll from jihadist attacks, ethnic killings and armed forces abuses that have become a defining feature of his presidency, despite thousands of French troops deployed since 2013 to contain the violence.

He faces two dozen candidates of which only one, Soumaila Cisse, 68, is seen as having a strong chance of ousting him. Both men are from the Saharan nation’s political elite, and IBK beat Cisse in a run-off at the 2013 poll.

Both held final rallies attracting thousands of people on Friday night.

“There is still a lot to do. That’s why I am soliciting the Malian people to give us another term, not because I’m thirsty for power,” Keita said at a rally on a leafy square on the banks of the Niger river.

“Everywhere I’ve been I see a desire for change. Malians want nothing more to do with this regime,” Cisse told his supporters at his party headquarters.

All candidates have promised to reverse Mali’s decline and help end pervasive poverty. Mali is 14th from the bottom on the U.N. Human Development Index, despite being Africa’s third biggest gold exporter and a major cotton grower.

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“RESIDUES OF TERRORISM”

A billboard in the exhaust fume-choked capital Bamako depicts Keita in flowing white robes and a skull cap, urging Malians to “consolidate the peace.”

Yet since he has been in power, violence has worsened. Civil society website Malilink recorded 932 attacks in the first half of 2018, almost double that for all of 2017 and triple 2015.

In the north, where French troops stepped in to halt a Tuareg rebellion and jihadi takeover before the last poll, jihadists have killed more than 160 U.N. peacekeepers.

Timbuktu, once a Sahara desert tourist spot, is unstable, hit by Islamist militants as well as tensions between Arab and Tuareg traders and black Malians from the south.

Islamist violence has also spread to central Mali, where militants have attacked the pan-regional G5 Sahel force. Killings have begun to take on an ethnic tone, as the Islamists exploit tensions over access to land and water.

Human Rights groups have unearthed evidence that Malian troops were implicated in mass graves in central Mali. The Defence Ministry pledged to investigate.

Keita has played down the country’s security woes.

“There are pockets of violence, residues of terrorism that even (French forces) ... haven’t managed to vanquish from Malian soil,” he said after a tour of Mali’s diaspora, one of about 150 costly foreign trips that have been criticised by opponents since he took office.

“Are you going to blame all that on IBK?”

LOW TURNOUT

Whoever is to blame, the violence could deter many from voting in a nation with consistently the lowest turnout in West Africa - about 40 percent on average.

“Violence in the Mopti region and northern region is really going to depress turnout,” said U.S. researcher Bruce Whitehouse.

Discontent with IBK is palpable, and thousands protested against him in Bamako last month. Yet he has the benefit of incumbency and is likely to win, although probably only in a second round, diplomats say.

Though most expect a smooth election, there is a risk of a disputed poll turning violent. Opposition candidates are crying foul over alleged tampering with the electoral list.

“I’m sad to see a government that cheats, to see an electoral fraud in the offing,” Cisse told Reuters after his rally. “But we don’t have a plan-B. We must go the polls.”

If Mali can avoid a rancorous dispute over the result, that will sooth anxieties.

“That’s the metric the international community will use: ‘there you go, we had a peaceful election’,” Adam Thiam, a Malian analyst told Reuters in Bamako.

“This election is all about showing Mali is stabilising.”