BOGOTÁ, Colombia — The two candidates of Colombia’s far-right and left wing parties came out ahead in a first-round vote on Sunday to choose the country’s next leader, setting the stage for a divisive presidential election, the first since the country signed a peace deal with its rebels.
Iván Duque, 41, a conservative former senator, won about 39 percent of the vote, election officials said Sunday night. Gustavo Petro, 58, a former leftist rebel who rose to become mayor of Bogotá, the capital, won about 25 percent.
The two, who came in ahead of three other major candidates, will face each other in a second and final vote on June 17.
Regardless of the winner, the election is expected to mark a big shift from the administration of Juan Manuel Santos, a centrist whom Colombians sent twice to the presidency and who won a Nobel Peace Prize in 2016 for negotiating a peace deal with the country’s main guerrilla group.
The peace accords were initially struck down by a narrow majority of voters, who were angered that it was too lenient on the rebels. Mr. Santos then passed a slightly revised deal through Congress shortly afterward, raised taxes and saw his approval rating plummet to 14 percent.
With no centrist candidate on the ballot, the June election will elect a president sure to be a polarizing figure.
“It’s a very stark division in this country,” said Cynthia J. Arnson, who studies Colombia at the Woodrow Wilson International Center for Scholars.
While politicians hoped the end of the war would reduce the frictions in Colombian politics, it seems the opposite is taking place. Bitter memories of a war which left at least 220,000 dead and divided families appears to have turned many voters against the traditional parties that brokered the accords.
A host of insurgent candidates challenged the establishment, making the postwar debate about a number of new, polarizing issues: gender rights, dealing with a crumbling Venezuela, the place of religion in politics and the role of a powerful ex-president, Álvaro Uribe.
Topping Sunday’s tally was Mr. Duque, an American-educated protégé of the conservative Mr. Uribe. The former leader remains one of the country’s most popular politicians and a staunch ally of the American war on drug traffickers. Mr. Duque has echoed his mentor’s platforms.
He has also called Mr. Uribe Colombia’s “eternal president,” raising concerns among critics that if Mr. Duque were elected, Mr. Uribe would have outsize power or even seek to change the Constitution to return to the presidency.
María Isabel Vivero, a 42-year-old consultant who voted for Mr. Duque, said she felt he would stake out his own path. “Uribe will consult, but he won’t govern,” said Ms. Vivero, who vented frustration with Mr. Santos and said she had voted against the peace deal.
The second-place candidate, Mr. Petro, represents a starkly different option. The son of a rural schoolteacher, Mr. Petro joined a guerrilla group at a young age, later putting down his arms after a deal with the government in the 1990s and entering left-wing politics.
He is best known as the mayor of Bogotá, where he governed until 2015. He passed gun restrictions that reduced crime, lowered the price of public transportation and offered free water to the poor.
He was also polarizing: An effort to take control of the country’s waste management left the capital buried in trash and ended in his being removed from office for a period. On the campaign trail he has been reluctant to criticize Venezuela’s left-wing leaders for growing authoritarianism and food shortages, which have sent at least large numbers of refugees into Colombia.
Delio Ruiz, a 53-year-old carpenter, said he was casting his vote for Mr. Petro because he thought he was the only candidate who would defend the poor. Mr. Ruiz lived in a working-class area founded by squatters, which benefited during Mr. Petro’s time in office.
“Petro put water in my community; he was the only one that came through,” said Mr. Ruiz on Sunday.
Michael Shifter, the president of the Inter-American Dialogue, said that while the peace deal remains controversial, the agreement with the left-wing rebels may have created an opening for Mr. Petro, the first hard-left candidate to make it to the second round of presidential voting in years.
“Petro seems to defy the political establishment,” he said. “The fact is you haven’t seen this challenge from the left in some time in Colombia.”
Susan Abad reported from Bogotá, Colombia, and Nicholas Casey from Caracas, Venezuela.