Polls have opened in the Philippines where voters are choosing from nine candidates for president.
Polling stations opened at 7am on Monday (23:00 GMT on Sunday) and will close at 6pm, with a winner potentially announced by late evening.
More than 17,000 congressional and local positions are also up for grabs and around 80 per cent of the country's 50 million registered voters are expected to cast ballots.
The country is using a computerised tallying system for the first time, but a computer glitch in the machines has fed suspicion of vote-rigging after tens of thousands of memory cards containing software for the machines from all over the country had to be replaced or reconfigured.
Al Jazeera's Veronica Pedrosa, reporting from the capital Manila, said according to the national election commission, testing of the new memory cards on Saturday went well and there were no new reports of faulty machines so all systems were a go for Monday's polls.
In the past four months, at least 24 people have been killed in election-related violence, according to police, and our correspondent said there continued to be scattered reports of political violence.
Liquor sales were banned for 48 hours from midnight on Saturday to reduce the chances of alcohol-fuelled violence, while security forces have set up checkpoints to arrest illegal gun holders.
In the presidential race, opinion polls indicate that Benigno Aquino III, a senator and the son of one of the country's democracy icons, has a two-to-one lead over his nearest rival, Joseph Estrada, the former movie star and ousted president.
But Aquino, whose father, Benigno Aquino Jr, was assassinated by soldiers in 1983, told thousands of supporters at a Manila rally on Friday that "this fight is not yet over".
Aquino's father was killed moments after stepping off a plane on his return from US exile to organise opposition to Ferdinand Marcos, the then president.
The killing triggered massive protests that culminated in the "people power" revolt in 1986 that toppled Marcos and installed widow Corazon Aquino as president.
Aquino's presidential bid was launched in the wake of an outpouring of sympathy for his family following the August 2009 death of his mother, Corazon.
The 50-year-old bachelor said he was confident he would win if the people are "allowed to vote and their votes are counted properly".
Estrada, 73, who was impeached, forced to step down amid massive anti-corruption rallies in 2001, and convicted of plundering the state before being pardoned by his successor, Gloria Arroyo, was "very optimistic" about his chances, Margaux Salcedo, his spokeswoman, said on Friday.
"He perceives this election as a way to vindicate himself and the Filipino masses," she said.
Also seeking the presidency is Manuel Villar, 60, another senator and the country's wealthiest politician.
A survey by the respected Social Weather Stations on May 3 gave Aquino 42 per cent support followed by Estrada with 20 per cent and Villar, 19.
Aquino campaigned on an anti-corruption platform, pledging a new style of clean government following nearly 10 years of Arroyo rule tainted by allegations of massive graft.
"The problems before us were caused by people putting their own selfish interests before the common good," Aquino told thousands of supporters on Friday.
Arroyo, who is required by constitutional term limits to step down, is due to hand over power on June 30.
But she is running for a seat in the lower house of congress, a contest she is expected to win.
Also in the mix is former first lady Imelda Marcos, 80, who gained global notoriety when thousands of her shoes were found in the presidential palace after her late husband Ferdinand's overthrow.
She is running for a seat in the lower house of congress as well.
World welterweight boxing champion Manny Pacquiao, 31, is aiming for a similar position in the southern island of Mindanao, where the country's worst-ever election-related violence occurred in November, when 57 people in a convoy, including 31 journalists, were abducted and executed over a suspected power struggle between two clans.