Voters in Colombia go to the polls on Sunday to decide whether a left-wing politician or a right-wing lawyer will succeed President Gustavo Petro.
Around 41 million eligible voters will choose between Senator Iván Cepeda of the governing Historic Pact (Pacto Historico) alliance and right-wing lawyer Abelardo de la Espriella of the Defence of the Homeland (Defensores de la Patria ) movement in a run-off election.
The campaign has been overshadowed by violence. In the run-up to the vote, there were several attacks in which civilians, soldiers and police officers were killed or injured.
That is putting the record of Colombia's first left-wing president to the test. While Petro and his camp point to social reforms and peace talks with armed groups, critics blame the government for the recent deterioration in the security situation.
De la Espriella unexpectedly won the first round with 43.7% of the vote. The conservative politician is campaigning for a tough line against guerrillas and organized crime as well as for free-market reforms. Cepeda scored 40.9% and has promised to continue key projects of the Petro government.
The election is also being watched closely in Washington. US President Donald Trump has publicly backed de la Espriella and described his election victory as important for relations between the two countries.
Polling stations close at 4 pm (2100 GMT), with initial reliable results expected later in the evening.
