Right-wing candidate Abelardo de la Espriella narrowly wins Colombia's presidential election

Right-wing candidate Abelardo de la Espriella has narrowly won Colombia's presidential election, an initial vote count shows, marking a dramatic shift in how the government will tackle the country's internal armed conflict and violence.

De la Espriella, who was endorsed by Donald Trump, has pledged a military crackdown on illegal armed groups, drug trafficking and crime.

He appeared to defeat left-wing Iván Cepeda, a close ally of the president, Gustavo Petro.

De la Espriella said "today begins a new stage for our country, a stage built on the free and democratic will of millions of citizens who chose to believe in a great, safe, prosperous Colombia full of opportunities".

With over 99% of votes counted, de la Espriella had won nearly 49.7% of the vote, while Cepeda won 48.7%, according to an initial count of the runoff election.

Cepeda has not conceded, saying the preliminary count was "not yet official or binding".

"Once the official canvass takes place and its final result is produced, and the corresponding verifications have been carried out, we will recognize the official result that emerges from that structure."

The verification process showed little difference to initial counting in the first round of voting on 31 May, Reuters news agency reported.

De la Espriella, who was raised in the Caribbean coastal region, enjoyed significant regional support there.

After the initial vote count came through, de la Espriella addressed a huge crowd of supporters who had gathered to celebrate in Barranquilla, a city on the coast.

"Tonight marks the beginning of a new story for the nation, tonight a new era begins, a change of order," said De la Espriella, who has nicknamed himself "El Tigre" (The Tiger.)

"I'm going to govern for all Colombians. For those who voted for me, and for those who chose the other candidate."

He also pledged loyalty to the country's 1991 constitution and said he would protect it.

De la Espriella's supporters donned the country's yellow football jersey and waved Colombian flags. They sang and danced to music from a stage lit up with photos of de la Espriella's face, chanting, "stand firm for the homeland" and "Petro out!", before a fireworks display.

Some wore hats akin to US President Donald Trump's supporters, but saying "Make Colombia Great Again!"

Trump responded to the result, writing on Truth Social: "He Won, BIG!"

"We are tired of the killings in this country. And tired of the bureaucracy of this government. We have a president from the coast!" one supporter, Patricia said.

"We are proud of The Tiger. We hope he will change the country, to a new one where we can have jobs, and more security above everything," another supporter said.

Supporters of Cepeda were also on the streets of Barranquilla, voicing their concerns over the tight win.

"There's a palpable sense of unease in the air," Catalina La Grande, a student and activist who supported Cepeda, told the BBC.

"Such a narrow margin also worries us, because it reflects how divided the country is and the enormous challenges we face in defending democracy, peace, and people's rights."

Maria, another young supporter of Cepeda, said the results showed the country was divided but said people had remained peaceful.

"There have been no violent incidents in the streets, which is positive considering the level of polarisation we are experiencing," she said.

The polarising differences between the two candidates have led to mounting fears that there could be unrest in the country after the result, especially if some critics do not recognise the result.

Late on Sunday, there were reports of clashes between protesters and police in Colombia's third-largest city Cali, with demonstrators burning US flags and police using tear gas to break up large crowds angry at de la Espriella's win.

Petro may challenge the result. He posted on X that "neither can be proclaimed president" after a "pre-count result" and demanded an audit of voting software, making allegations that some polling stations were "compromised", without providing evidence.