El Salvador's presidential runoff was hung up in a near tie between an ex-guerrilla leader and an arch conservative mayor as tension mounted over who would be proclaimed the winner.
Preliminary results showed Salvador Sanchez Ceren, of the ruling Farabundo Marti National Liberation Front (FMLN), edging out conservative candidate Norman Quijano by 6,634 votes, making his lead 50.11 percent to 49.89.
We're not going to allow them to steal the election from the people. They are not going to steal this victory. We will fight, if necessary with our lives.
Quijano, a former mayor of San Salvador and candidate of the right-wing Nationalist Republican Alliance (ARENA) party, said in a tweet on Monday that he wanted a "vote-by-vote" recount, calling the election tribunal biased and insisting he was the president-elect.
"The behaviour of the Supreme Election Tribunal has never been clean; they were tainted before and during the electoral process," Quijano said.
He also asked the country's attorney general to guard all electoral material and urged international observers to remain in for El Salvador a few more days.
He warned on Sunday that the armed forces were watching the election process.
Eugenio Chicas, head of the tribunal, said the law did not allow for a vote-by-vote recount, but that a recount of disputed polling stations would begin on Tuesday.
"We're not going to allow them to steal the election from the people," Quijano told reporters. "They are not going to steal this victory. We will fight, if necessary with our lives."
The Supreme Electoral Tribunal said it would not announce a winner until a manual count had been completed.
"The FMLN and ARENA parties have a long and bitter history," Al Jazeera's David Mercer, reporting from San Salvador, said.
"Their rivalry dates back thirty years, to a civil war which pitted leftist rebels against a US-backed military government. Both parties were born from the conflict, and stepping out of the war’s shadow will not be easy," he said.
The election results highlights divisions in the country, two decades after a war that killed about 75,000 people.
While Quijano's comments are viewed as inflammatory political rhetoric, some saw them as a tactic to undermine the result.
"I take it seriously as a political tactic rather than as a literal call, though I was troubled by his call to the army," said Hector Perla, an expert on Central America at the University of California Santa Cruz.
"All the rhetoric indicates that they are not going to accept, even if they do have the recount, they are not going to accept this other legitimate outcome," he told the AFP news agency.
Nearly three million votes will be re-counted over the coming days, with official results expected by Thursday.