Nigeria's President Muhammadu Buhari has won a second term in office after a contentious Nigerian election this weekend, but the opposition are refusing to accept the outcome and a period of uncertainty and unrest could follow.
That could impact the OPEC member's oil production, according to RBC Capital Markets' Global Head of Commodity Strategy Helima Croft.
"With the opposition alleging fraud and refusing to the accept the outcome, the risk of further unrest remains high in the weeks ahead, especially in the restive oil region, which was the scene of some of the worst Election Day unrest," Croft said in a note Wednesday co-authored with RBC analysts Christopher Louney, Michael Tran and strategist Megan Schippmann.
"If this election does bring a return to militancy in Nigeria's oil region and major infrastructure attacks, it would be a very material event for the oil market, with two OPEC countries (Venezuela and Iran) under U.S. sanctions and Saudi Arabia continuing to cut production," they noted.
"Given the premium that the American president places on low oil prices, he will need to hope that Nigeria does not revert to past practice."
Nigeria's election last weekend did not run smoothly and was marred by delays, logistical problems, outbreaks of violence and deaths, and allegations of vote rigging.
Buhari, who leads the All Progressives Congress (APC), won the election with almost 15.2 million votes (or 57 percent), the country's Independent National Electoral Commission (INEC) announced Tuesday evening. Buhari's nearest rival, Atiku Abubakar, who heads the People's Democratic Party (PDP), received around 11.2 million votes, or 42 percent.
INEC, which made the decision to postpone the election for a week due to operation and logistical challenges, said that it had been made aware of irregularities prior to the election — although it has itself been the target of accusations from both the main parties, accusing it of trying to influence the result in favor of the other.
Nigeria is a significant oil and gas producer — the largest in Africa — and has the highest output among OPEC's African members, producing almost 1.8 million barrels a day (mb/d) in January, according to the latest data from OPEC.
Nigeria is seen as one of the "fragile five" members of OPEC, however (along with Iran, Iraq, Libya and Venezuela) because its oil-rich Niger Delta region in the south of the country has been plagued with long-running unrest and disruption to, and sabotage of, its oil production from militant groups.
There are a handful of militant groups operating in the region, including the Niger Delta Avengers, Niger Delta People's Volunteer Force and the "Movement for the Emancipation of the Niger Delta," or MEND. They say that their region's oil wealth and environment is being exploited by foreign oil companies and the Nigerian government.
What's more, the Niger Delta region is a stronghold for the opposition PDP and violence in the region ahead of the election was pronounced with several deaths, including that of one of the electoral commission's staff who was reportedly shot on election day.
Any disruption to its oil sector could have an impact on wider oil markets and price volatility, especially with output lower from Venezuela and Iran. President Donald Trump has repeatedly criticized OPEC and its allies for oil price rises.
Benchmark Brent crude futures were trading at $65.58 per barrel Wednesday while West Texas Intermediate (WTI) futures stood at $55.92.
With the PDP rejecting the results and continuing questions about the credibility of the polls, RBC's Croft and her team said they believe there is a high risk of further bloodshed in the coming weeks, especially in Nigeria's oil region.
"This time, we will be closely watching what transpires in the Niger Delta given the problems that occurred there on Saturday as well as the historical role that elections have played in giving rise to armed groups that have sabotaged the energy infrastructure and caused large-scale supply disruptions," they said.
"The Niger Delta Avengers had vowed to cripple the Nigerian economy if Buhari were re-elected, and previous election cycles have been accompanied by the rise of armed groups that attacked the energy infrastructure and shut in 800,000 b/d to 1 million b/d for varying periods."
State elections scheduled for March 9 could further add to the volatility in the oil region, experts note, and political uncertainty should be expected as the opposition PDP is likely to challenge the election result.
"While the opposition is highly likely to challenge the results in court, alleging massive voter fraud, the potential for violence to erupt in the immediate aftermath of the vote remains limited. However, there is potential for violence, including in the oil-producing Niger Delta region, in the context of the upcoming state-level elections on 9 March," Malte Liewerscheidt, West Africa analyst at risk consultancy Teneo Intelligence, said in a note Tuesday.
However, not all analysts agree and some say that threats of more disruption could be bluster. Nigeria is unlikely to descend into another period of oil sabotage regardless of won the election at the weekend, experts told CNBC last week.