Colombia's pro-talks President Juan Manuel Santos faced a strong election challenge on Sunday from a far-right candidate. Oscar Ivan Zuluaga claims that a settlement pact would lead to more "manipulation" by the rebels.

The Revolutionary Armed Forces of Colombia (FARC) emerged as a Marxist peasants' defense group in the 1960s. Latin America's longest-running conflict has claimed the lives of an estimated 220,000 people.

In first-round voting last month, Zuluaga won nearly 30 percent of the ballots. Santos of the center-right coalition National Unity party garnered 25 percent.

Zuluaga (pictured right) had argued that Santos (left), if re-elected, could be "manipulated by the FARC" and asked voters to decide whether they wanted "change to improve Colombia."

Last Monday, FARC began a ceasefire that is due to last until June 30.

Santos, who launched the talks with the rebels in 2012, said voters could choose between him as a candidate - who wanted the decades-long war to end - and "those who reject peace."

Campaigning with football

On Saturday, Santos campaigned by referring to World Cup football in Brazil.

"We've got our team. We've got our way to win. Tomorrow, peace is going to be the winner," he said.

Zuluaga viewed Colombia's 3-0 win against Greece at home with family and his political mentor, ex-president Alvaro Uribe.

More than 32 million Colombians are eligible to vote. In the first round, about 60 percent of voters did not cast ballots.

Analysts said the level of turnout on Sunday could be decisive in determining the election outcome.

ipj/slk (AFP, dpa)