Polls started to close Sunday in Colombia's presidential election, a high‑stakes vote that could bring further peace talks with armed groups or a hard‑right military crackdown.

Pre‑election polls showed left‑wing senator Ivan Cepeda narrowly ahead but facing a strong challenge from hard‑right lawyer Abelardo de la Espriella.

The vote is, in part, a referendum on outgoing President Gustavo Petro and his "total peace" policy of negotiating with guerrillas and other drug trafficking groups.

A decade after a landmark peace accords, pockets of Colombia are still ruled by dissident armed groups that dominate world cocaine production.

Critics say Petro's strategy has given these gangs free rein, causing surging violence and record drug exports.

This presidential campaign was marred by car bombs, drone attacks, and the assassination of one leading presidential candidate, Miguel Uribe.

"This government really strengthened armed groups by being so soft," said Catalina Devia, a 42‑year‑old advertising executive and mother of two who voted for De la Espriella.

"Many Colombians are thinking about emigrating" she said.

Rightwing frontrunner De la Espriella, 47, is a pro‑Trump outsider who calls himself "The Tiger".

He has campaigned behind bullet‑proof glass and vowed to confront armed groups in the air, on land and at sea -- mimicking rhetoric that has swept the right to power across Latin America.

"We are going to win in the first round," De la Espriella said after casting his ballot.

But first he must overcome Cepeda, 63, the son of a leftist senator killed by right‑wing paramilitaries.

Cepeda is backed by President Petro, who is constitutionally barred from re‑election, and draws support from voters who credit the government with helping the poor.

They have praised Petro for raising the minimum wage, boosting education spending and transferring land to the poor.

"I think we've done quite a lot in terms of education… protecting the environment, social justice, and defending human rights," said Pedro Barragan, a 52‑year‑old teacher voting in central Bogota.