Pre‑election polls showed left‑wing senator Ivan Cepeda leading, but facing a strong challenge from hard‑right lawyer Abelardo de la Espriella, a pro‑Trump outsider.The vote is in part a referendum on Colombia's first leftist president, the outgoing Gustavo Petro, and his signature "total peace" initiative of negotiating with guerrillas and drug traffickers.Experts say armed groups used his peace overtures to amass more territory and produce record amounts of cocaine.

Women ride past an armoured personnel carrier as Colombians vote for president in the shadow of the worst violence in a decade © JOAQUIN SARMIENTO / AFP

The election campaign was marked by car bombs, attack drones, the assassination of one leading presidential candidate and threats on the lives of others.De la Espriella -- self-styled as "The Tiger" -- addressed rallies behind bullet-proof glass. He wants to confront armed groups in the air, on land and at sea, echoing hard-line rhetoric behind recent right-wing wins elsewhere in Latin America.On Sunday, the 47-year-old millionaire called the election "the most important battle in the republic's history" and claimed he could pull off an outright win, avoiding the June 21 runoff that polls suggest will be necessary."This government really strengthened armed groups by being so soft," said Catalina Devia, a 42-year-old advertising executive and mother of two, who is considering emigrating if Cepeda wins.- Fear of war returning - Petro is constitutionally barred from running and has backed 63-year-old Cepeda -- the son of a senator killed by right-wing paramilitaries.