Former First Lady Sandra Torres is currently ahead in the Guatemalan elections following the release of partial results.
Around 49% of the votes have been counted so far. Ms Torres has just under 24% of the vote while her closest rival, Alejandro Giammattei, has 15%.
Nineteen candidates are seeking to succeed President Jimmy Morales.
The election is not expected to yield an outright winner, as candidates need to win over 50% of the vote.
Around 40,000 police officers were on duty during voting amid fears of violence.
In San Jorge in the east of the country, voting was suspended after death threats were made against electoral authorities, according to Interior Minister Enrique Degenhart.
Gang violence and poverty have been the main topics that dominated campaigning.
Thelma Aldana, the former attorney-general, and Zury Ríos, the daughter of the late military ruler Efraín Ríos Montt, have been barred from running for the presidency. Another candidate was arrested in Miami on suspicion of conspiring to import cocaine to the US.
Here is a look at the candidates and the main issues.
Who’s being elected?
Source: Guatemalan Supreme Electoral Tibunal
How does it work?
The president is elected by absolute majority for a single four-year term. Under Guatemalan law, current President Jimmy Morales cannot stand for a second term.
If no candidate gets more than 50% in the first round on 16 June, the top two candidates will go through to a second round on 11 August.
Nineteen candidates are competing for the presidency, down from the original 24.
Who are the top candidates?
Sandra Torres: ‘Leaving a loving marriage for the sake of a nation’
Sandra Torres, 63, is hoping it will be third time lucky for her. She failed in her two previous attempts to be elected president, but the most recent opinion polls put her in the lead.
Ms Torres was married to Álvaro Colom, who governed Guatemala from 2008 to 2012, and who is currently under investigation for alleged fraud.
She divorced him in 2011 in order to bypass a law which banned close relatives of the president from succeeding him. At the time, she said: “I’m divorcing my husband, but I’m getting married to the people”.
She also said that she had found it “very difficult” to leave her “loving marriage” to Mr Colom.
In 2011, her candidacy was rejected by the Constitutional Court, but she was allowed to run in 2015. That time, she had enough votes to get her into the second round where she was defeated by Jimmy Morales by a large margin of almost 35 percentage points.
Ms Torres is running for the social-democratic National Unity of Hope party (UNE).
She and her party are under investigation for alleged illegal campaign financing during the last election, which she has denied.
Ms Torres says she will provide “comprehensive solutions like development, fight against poverty and job opportunities” to try to convince Guatemalans to stay in the country rather than migrating to the United States.
The former First Lady has also pledged to deploy troops in Guatemala’s streets to crack down on drug gangs.
Alejandro Giammattei: ‘Wall of prosperity’
The 63-year-old candidate is standing for the right-wing Vamos (Let’s Go) party and this is his fourth attempt at becoming president. Each time, he has run for a different party.
Mr Giammattei is a trained doctor who was named director of the Guatemalan prison system in 2006.
That same year, he led a controversial operation to take control of the Pavón prison, which had been run by inmates for a decade. Seven inmates died during the raids by the security forces.
Mr Giammattei was among eight people accused over the incident and after spending 10 months in pre-trial detention, he was acquitted due to lack of evidence.
He came fourth in the 2015 election.
He says that if he is elected he will build “a wall of prosperity” to keep Guatemalans from migrating to the US.
In order to lessen the disparity between the rich and the poor, he wants to attract more foreign investment to Guatemala by strengthening the protections granted to private property.
Roberto Arzú: ‘Make Guate great’
The 49-year-old conservative businessman wants to follow in the footsteps of his late father Álvaro, who governed Guatemala from 1996 to 2000.
Roberto Arzú has never held public office but did preside over one of Guatemala’s most successful football teams. He has had a string of businesses ranging from sports centres to shopping malls.
The outgoing president, Jimmy Morales, named him ambassador with a special mission to promote trade between Guatemala and South America.
He is standing for a coalition made up of the PAN and Podemos parties. His motto has been “Make Guate great!” using the shortened word for Guatemala and imitating US President Trump’s campaign slogan.
He has campaigned mainly on security issues, saying that he will crack down on crime.
A judge in Florida has ordered his arrest over an outstanding debt he owes to Miami-based political campaign strategist JJ Rendón. Mr Arzú says he never signed a contract with Mr Rendón and is therefore not liable for the breach of contract payment.
What are the main issues?
Polls suggest many voters are undecided and the election outcome is therefore hard to predict.
The election has been overshadowed by the constitutional court deciding to bar two frontrunners – Thelma and Zury Ríos – from standing.
Ms Ríos was barred under a provision of Guatemala’s constitution which prevents the close relatives of coup leaders from serving as president.
Ms Aldana, meanwhile, has been charged with embezzlement, lying and tax fraud. She denies any wrongdoing.
Guatemalans have told pollsters that their top concern is government corruption.
Four years after large-scale anti-corruption protests forced then-President Otto Pérez Molina to resign, many Guatemalans feel not enough has been done by the government of Jimmy Morales to combat corruption.
Mr Morales caused outrage when he tried to kick the UN-backed anti-corruption commission out of Guatemala when it investigated him over alleged corruption.
The most vocal supporter for the commission, known as CICIG by its Spanish initials, has been Thelma Aldana, who as Guatemala’s attorney general has worked closely with it. Before she was barred, she said she would strengthen CICIG and make government more efficient and transparent.
Mr Arzú, on the other hand, has been openly critical of the CICIG, accusing it of “violating national sovereignty”, and Mr Giammattei said he was opposed to the commission because “justice must be from Guatemalans, for Guatemalans, by Guatemalans”.