Some of Nigerian presidential candidates.

The last-minute delay of Nigeria’s general elections by a week carries dangers for both President Muhammadu Buhari and his main opponent, Atiku Abubakar.

While the electoral commission said the postponement just over five hours before polls were due to open Saturday was for logistical reasons, it reinforces opposition criticisms that state institutions under Buhari aren’t independent and are incompetent. The threat to Abubakar’s campaign is that the delay will discourage voters in areas where he needs a high turnout to win. Millions of Nigerians had traveled to their hometowns to vote.

The decision early Saturday may heighten tensions in what has been a tight race in Africa’s biggest democracy between Buhari, a 76-year-old former military ruler, and businessman and ex-vice president Abubakar, 72. Analysts were split down the middle over who would win. Both Buhari’s All Progressives Congress and Abubakar’s People’s Democratic Party condemned the delay.

“There is a possibility that popular anger and the manner of the postponement could galvanize more people to come out to vote,” said Cheta Nwanze, head of research at SBM Intelligence in Lagos, the commercial capital. “If there is a higher turnout then, the PDP will win the election. But if the turnout is successfully repressed, the APC will win.”

Buhari is leaving his hometown of Daura, in Katsina state, where he had traveled to vote, to return to the capital, Abuja, his personal assistant Bashir Ahmad said on Twitter.

Buhari Disappointed

The president said he was “deeply disappointed” with the postponement after the electoral body’s “assurances, day after day and almost hour after hour that they are in complete readiness for the elections. We and all our citizens believed them.” In a statement, he urged the commission to “ensure a free and fair election.”

His opponent Abubakar described the delay as part of a plot by Buhari’s APC party to ensure a low turnout.

“I call on all Nigerians to be patient,” Abubakar, who had traveled to his northeastern hometown of Yola, said in a statement. “We have tolerated the maladministration of this government for four years. We can extend our tolerance a few more days and give them our verdict via our votes.”

Investor Concern

An expectation that the vote would go smoothly bouyed Nigerian equities and bonds in recent weeks. The stock market is up 7.1 percent this month, the second-best performance globally, according to data compiled by Bloomberg. Investors may turn bearish next week if they think the delay was down to political machinations, according to Robert Omotunde, head of investment research at Lagos-based Afrinvest West Africa Ltd.

Independent National Electoral Commission Chairman Mahmood Yakubu announced the postponement at about 2:45 a.m., saying “proceeding with the election as scheduled is no longer feasible.” He said INEC would hold a meeting with the parties at 2 p.m. and refused to answer questions about the commission’s decision.

“Some of it is incompetence, frankly,” said Amaka Anku, Africa analyst at Eurasia Group. “You put someone in charge of something and they say yes everything is fine until they can’t cover up anymore.”

Nigerian elections are regularly postponed. A week before the 2015 presidential and parliamentary vote, it was moved back by more than a month. Buhari went on to win and become the first opposition candidate to take power through the ballot box in Africa’s biggest oil producer. The vote four years before was delayed after balloting had already started.

Heightened Distrust

The postponement “will almost certainly create an environment of heightened anxiety and distrust,’’ Ronak Gopaldas and Ryan Cummings, directors of Cape Town-based Signal Risk, said in an emailed response to questions. “Allegations of vote-rigging and electoral manipulation will inevitably follow, with opposition threats to boycott the vote possible.”

U.S. Secretary of State Michael Pompeo spoke to Buhari and Abubakar on Friday, telling them that “the conduct of the elections is critical for the future of democracy in Nigeria and across Africa,” according to the State Department.

Polling centers were initially meant to open Saturday at 8 a.m., with more than 84 million registered voters across 36 states and the federal capital.

“This thing would have dampened people’s optimism,” said Peter Eduwaye, a 55-year-old doctor in Lagos. “I think we will get a lower voter turnout next week compared to what it would have been today.’’