Calmest polls in half a century of conflict in Colombia, with the former rebel movement FARC spurning jungle warfare for politics, and the ELN – the country's last active rebel group – observing a ceasefire.
Colombians cast their votes on Sunday to elect a new congress with a resurgent right, bitterly opposed to a peace deal that allows leftist former rebels to participate, expected to poll strongly.
The election was the calmest in half a century of conflict in Colombia, with the former rebel movement FARC spurning jungle warfare for politics, and the ELN – the country's last active rebel group– observing a ceasefire.
President Juan Manuel Santos said the polls were "the safest, most transparent elections" in the country's recent history shortly before polls closed at 2100 GMT (4:00pm) after eight hours of peaceful voting.
"This is the first time in more than half a century that the FARC, instead of sabotaging the elections, are taking part in it," he said, adding that the ELN had "respected" their ceasefire.
Without giving figures, Santos also hailed "massive participation" in the election, in a country where abstention traditionally runs at around 60 percent.
Full results are expected on Monday.
Presidential candidates decided
However, by late on Sunday voters had already chosen the candidates from the right-wing and leftist coalitions who will contest the presidential election in May, following primaries held in parallel to the legislative vote.
Ivan Duque of the Centro Democratico party headed by senator and former president Alvaro Uribe, won the right-wing primary with more than 2.7 million votes, or 67 percent of the poll, and will spearhead hard line opposition to the peace deal.
Gustavo Petro, a former Bogota mayor who is seeking to become conservative Colombia's first leftist president, will oppose him after winning nearly two million votes, 85 percent of the poll, in his primary.
Meanwhile, the public prosecutor's office said it would open an investigation into why electoral officials ran out of ballot papers for the party primaries.
The peace accord with the Revolutionary Armed Forces of Colombia (FARC) guarantees their new political party 10 of the 280 seats in the new congress.
The party uses the same Spanish acronym, which now stands for the Common Alternative Revolutionary Force, and replaced its crossed-rifles insignia with a red rose.
"It's the first time in my life that I've voted and I do it for peace," said Pablo Catatumbo, a former FARC commander who is assured a senate seat.
Opinion polls give the FARC little chance of adding to its 10 free seats, following a disastrous campaign during which its rebels-turned-politicians were largely drowned out by a tide of public revulsion over crimes committed during the conflict.
Maria Maldonado, a 65-year-old pensioner who voted in Bogota, was in no mood to forgive and forget.
"I have a lot of memories. Of all the compatriots who were murdered and buried, and nothing happened. And now we're going to allow these people manage us knowing that they have left us so many tragedies?" she said.
With the left divided, the stage is set for hard line conservatives who oppose the agreement to win an absolute majority in congress, and push on to win the presidential election in a few months.
Uribe victory predicted
Opinion polls predict a triumph for ex-president and senator Alvaro Uribe and his Centro Democratico party, along with other parties opposed to the peace agreement that has polarised the South American country.
Under the peace accord, FARC disarmed its 7,000 fighters in order to join the political process, agreed to confess to wartime crimes and pay reparations to victims.
This infuriates many Colombians, in particular the right wing, which is vowing to win the presidential election and amend the peace deal.
But much of the peace agreement has already been implemented, including the rebels disarming and demobilising.
Analysts say a hard-right government could block the implementation of the rest of the pact, including agrarian reform and the special justice deal under which repentant rebels can avoid jail by paying reparations.
"The mere fact of not applying what has been signed would be enough for this agreement to be ineffective," said Frederic Masse, an expert on the conflict at Colombia's Externado University.
Santos, who signed the peace agreement with the FARC in November 2016, is stepping down as president in August after two terms.
The first round of the presidential election is set for May 27, with the run off planned for June 17.
Sunday's elections were held against the backdrop of economic concern in Colombia, which registered 1.8 percent growth in 2017, its weakest for nearly a decade.
Candidates were angered when officials ran out of ballot papers for the primaries, citing budgetary problems.
"Due to budget problems, not all cards were printed," elections registrar Juan Carlos Galindo told reporters. Only 15 million cards were printed for an electorate of 36 million, he said.
Galindo said he had approved of photocopies being used for polling stations where the cards had run out.
Finance Minister Mauricio Cardenas, whose office manages to election budget, said the number of printed ballots were made based voters' records in Colombia, where abstention typically runs to around 60 percent.