Former first lady Sandra Torres was in the lead after partial results from Guatemala's presidential election, following a tumultuous campaign that saw two leading candidates barred and the top electoral crimes prosecutor flee the corruption-weary country.
With 28 per cent of votes counted after Sunday's polls, Torres was on 24 percent while her closest rival Alejandro Giammattei was on 15 percent, the Electoral Supreme Court (TSE) said.
With a crowded field of 19 candidates, counting has been slow and no one is expected to poll more than the 50 per cent required to avoid a runoff on August 11.
After casting her ballot, Torres, of the center-left Unity of Hope party (UNE), said she was "optimistic, we've worked hard ... I'll be the first woman president." Her closest rival, Giammattei, a doctor from the conservative VAMOS party, denounced an "irregular" electoral process after several candidates were excluded from the race to succeed unpopular outgoing president Jimmy Morales.
Morales had called on Guatemalans to turn out in droves to vote, but when he did so he was accosted by a young man who blasted him for being "the worst president in Guatemala's history." Morales, sporting a Guatemala football jersey, kept his calm, replying: "May God bless you, my friend." Voting went smoothly, apart from a few isolated exceptions, the TSE said.
In San Jorge, a town in the eastern Zacapa department where drug traffickers are particularly active, voting had to be suspended due to death threats made against electoral authorities, Interior Minister Enrique Degenhart said.
More From This Section
Eight million Guatemalans were eligible to vote and some 40,000 police were on duty for the election, with the military deployed to guard "critical points", including prisons.
Separately, police arrested former general Luis Mendoza in the town of Salama after he had cast his ballot.
He is accused of participating in massacres of indigenous people during Guatemala's civil war from 1960 to 1996.
Gang violence, poverty and news of the streams of US-bound Guatemalan migrants dominated campaigning.
The country's top anti-corruption campaigner, former attorney general Thelma Aldana, is not among the candidates.
She was expected to poll strongly, but was barred from running last month over allegations of irregularities dating from when she was a barnstorming public prosecutor.
Torres, a 63-year-old businesswoman, led opinion polls but was a polarizing figure from her years as first lady, and analysts believe she would struggle in a second round, given Giammattei's ability to unify the conservative vote against her.
Guatemalans also voted in congressional and municipal elections.
Torres's UNE is expected to poll strongly but fall short of a majority in the deeply fractured 160-seat Congress.
The ex-wife of former president Alvaro Colom, in power from 2008-2012, Torres has pledged health and education reforms as well as jobs to stem the flow of migrants to the US. She has vowed to oppose abortion and same-sex marriage.
Giammattei has vowed to bring back the death penalty to help crush violent gangs, fight poverty to stop migration and end "disgusting" corruption.
Three other candidates are vying for third place, with indigenous contender Thelma Cabrera building momentum as the campaign came to a close.
Monitors from the Organization of American States (OAS) led by former Costa Rican president Luis Guillermo Solis supervised the polls.
Whoever succeeds Morales faces a tough challenge tackling gang violence and poverty in Central America's most populous country.
Guatemala has one of the world's highest homicide rates: official statistics put it at 22.4 murders per 100,000 people at the end of 2018.
Around half the killings are blamed on drug trafficking and extortion operations carried out by powerful gangs.
Morales, a former TV comedian who beat Torres in a 2015 run-off, is obliged to step down under Guatemala's one-term rule.
His predecessor Otto Perez is in jail for corruption and he himself faces a graft inquiry into illegal campaign funding.
That was instigated by Aldana and the UN-backed International Commission Against Impunity in Guatemala (CICIG), which has put former presidents, ministers and business moguls in jail.
Aldana -- who fled to the United States after receiving death threats -- told AFP her exclusion was orchestrated by those she put in prison and their allies, who saw her as a "hindrance." Also barred from running was Zury Rios, daughter of late dictator Efrain Rios Montt, under constitutional rules that prevent his relatives from seeking the presidency.
And as polling stations were being prepared across the country, Oscar Schaad, the electoral court's top prosecutor, said he had been forced to flee the country, citing threats to him and his family.