KABUL — Voter turnout in Afghanistan’s presidential election over the weekend was less than half of what it was the last time Afghans chose a president, officials estimated Sunday, a dismal showing that threatened to weaken the next government no matter who is declared the winner.

With just over half the votes counted, Afghanistan’s Independent Election Commission estimated that only 2.2 million out of 9 million registered voters cast ballots in the election Saturday, the country’s fourth. The last presidential election here was in 2014.

“The turnout was the lowest than any other election in the past 18 years,” said Sughra Saadat, program manager of the independent Transparent Election Foundation of Afghanistan. “The turnout was low even in secure areas where more people voted in the past.”

A combination of security concerns, fear of fraud and voting irregularities kept people away, election monitors said. The two front-runners were President Ashraf Ghani, who is a seeking a second term, and Abdullah Abdullah, the country’s chief executive. Preliminary results aren’t expected before Oct. 17; final results are due Nov. 7.

“The low turnout underscores two of Afghanistan’s greatest challenges, which have haunted Afghanistan for years: the relentless threat of violence and popular mistrust of political leaders,” said Michael Kugelman, a researcher with the Wilson Center. 

Participation was still lower among women, Sadaat said. She blamed a drop in female turnout in part on a new requirement that all voters be photographed at the polling sites.

Women in some conservative rural areas and their male relatives objected to this requirement, which authorities said was added to prevent identity fraud. Tribal and religious customs in such areas, especially among ethnic Pashtuns, forbid exposing women to men to whom they are not related or to the public. Women may leave home only if covered in full-face burqas.

“Based on our preliminary findings, women voters can’t be more than 20 percent,” Saadat said. “Whereas they made up 38 percent of the voters in 2014 election.”

Scott Worden, director of Afghanistan and Central Asia Programs at the U.S. Institute of Peace, said “while the day was not as violent as people feared and there were few casualties, the Taliban were successful in suppressing the vote through threats and restricting access to the polls.”

Five people were killed Saturday and 76 wounded in attacks across the country, according to the Defense Ministry.

Worden described the low turnout as a “mixed blessing.” It means “only a small number of Afghans will have a say in who the next president is,” he said, but “there was not the massive chance for fraud” that has ruined previous elections here.

“There was a smaller total but a potentially more legitimate result,” he said.

 The top priority for the winner will be to secure a peace deal with the Taliban — but the low turnout could undercut the next president’s claim to a seat at the negotiating table.

Ghani faced pressure to delay the election while the Taliban and the United States negotiated a deal. Ghani resisted, saying a vote was necessary to give the government a mandate to negotiate directly with the Taliban. The Taliban have long dismissed officials in Kabul as American puppets.

The U.S.-Taliban talks collapsed this month. The Taliban have not indicated that they would be willing to sit down with the next government.

“Assuming there are no credible complaints about fraud and a clear winner comes through either on the first or the second round, it would be good if the new president understood that his mandate is partial,” said Kate Clark, a researcher with the Afghan Analysts Network.

She said a large number of Afghans did not vote either because they live in Taliban-controlled areas or because they were apathetic about the candidates running. 

The head of the Afghan Independent Election Commission, Hawa Alam Nuristani, said the vote Saturday was “the healthiest and fairest election in comparison to the previous elections.” Afghanistan has held four presidential elections and two legislative elections since civilian rule was restored in 2001.

With the voting complete, many now fear a drawn-out period of political wrangling. After the 2014 presidential election, in which Ghani and Abdullah were the front-runners, the country was thrown into a months-long political crisis amid allegations of fraud. A European Union report later raised fraud concerns related to about a quarter of all votes cast in that election. 

A presidential candidate needs more than 50 percent of the vote to win. If no candidate meets that threshold, a second round of voting must be held within two weeks of the release of the official results.

Sayed Salahuddin and Sharif Hassan contributed to this report.