Colombian voters put the country’s peace negotiations with FARC guerrillas on shaky ground in Sunday's presidential election, as former finance minister Óscar Iván Zuluaga finished ahead of incumbent Juan Manuel Santos in a field of five candidates.

Neither candidate won more than 50 percent of the vote, so the two will go head to head in a high-stakes runoff June 15.

Zuluaga, the protégé of powerful ex-president Alvaro Uribe, has pilloried Santos for engaging with FARC rebel commanders in talks that began 18 months ago in Cuba, bringing the country closer than ever to an end to Colombia’s half-
century of civil strife.

“We can’t let the FARC run our country from Havana,” Zuluaga told supporters in a written speech after his victory. “We can’t have a president who is manipulated by the FARC, the biggest drug traffickers in the world.”

Zuluaga had 29.2 percent of the votes, while Santos received 25.6 percent.

Conceding the loss, Santos told supporters that Colombians will face a choice June 15 “between those who want to end the war and those who want the war to go on forever,” drawing chants of “We Want Peace! We Want Peace!”

Balloting in Latin America’s third-most-populous nation proceeded smoothly and without irregularities, but fewer than 40 percent of eligible voters came to the polls. Six percent of ballots cast were left blank, apparently in protest.

Former defense minister Marta Lucía Ramirez and leftist candidate Clara López had a stronger-than-expected showing, each winning with more than 15 percent. Former Bogota mayor Enrique Peñalosa received 8.2 percent.

Zuluaga and Santos have three weeks to win over their supporters. López and Peñalosa are in favor of the peace talks; Ramirez is not.

Zuluaga’s win suggests that many here are nostalgic for Uribe’s strong hand and folksy, tough-talking manner. Although Santos has kept Colombia’s economy purring, he has strained to connect with ordinary Colombians, and many are deeply skeptical of his engagement with FARC guerrillas whom the government considers terrorists.

Zuluaga’s “Peace without impunity” slogan had cachet with Uribe loyalists such as Maria Escobar, 53, who said Santos is going soft on the FARC for his own political advantage.

“Uribe had the guerrillas under control, and these negotiations are a farce,” said Escobar, who described herself as a housewife struggling to make ends meet. She voted for Zuluaga because she said he “thinks like Uribe — that the bad guys should go to jail or pay with their lives.”The peace talks have been the race’s only real wedge issue. Both Santos and Zuluaga are conservatives who would deepen Colombia’s free-trade partnership and preserve close relations with the United States.