Cristina Fernández de Kirchner, who served as the country's president, is at the centre of a corruption case, prompting her supporters to gather in front of her home every night for weeks.
An attempt at killing Argentina's Vice President Cristina Fernández de Kirchner outside her home failed because the handgun misfired, the country's president said.
The man who tried to assassinate the powerful politician, a former president herself, was quickly overpowered by her security officers in the incident Thursday night.
President Alberto Fernández said the pistol did not discharge when the man tried to fire it.
"A man pointed a firearm at her head and pulled the trigger," the president said in a national broadcast following the incident. He said the firearm was loaded with five bullets but "didn't fire even though the trigger was pulled."
The vice president did not appear to have suffered any injury, and the man was overpowered within seconds as he stood among a crowd of her supporters.
President Fernández called it "the most serious incident since we recovered democracy" in 1983 after a military dictatorship and urged political leaders and society at large to repudiate the attempted shooting.
The attack came as Vice President Fernández de Kirchner is facing a trial for alleged acts of corruption during her 2007-2015 presidency — charges that she vehemently denies.
The case against Fernández de Kirchner, often referred to by her initials CFK, has led her supporters to surround her home in the upscale Recoleta neighbourhood of Argentina's capital.
Video broadcast on local television channels showed Fernández de Kirchner exiting her vehicle surrounded by supporters when a man is seen extending his hand with what looks like a pistol. The vice president ducks as people around the apparent gunman appear shocked at what is happening.
An unverified video posted on social media shows the pistol almost touching Fernández de Kirchner's face.
'Threat to democracy'
The alleged gunman was identified as Fernando André Sabag Montiel, a Brazilian citizen, said an official at the Security Ministry, who spoke with AP on condition of anonymity.
He does not have a criminal record, the official said. adding that the weapon was a .32-calibre Bersa Thunder, a compact handgun made in Argentina.
The president declared Friday a holiday "so the Argentine people can, in peace and harmony, express itself in defense of life, democracy and in solidarity with our vice president."
Supporters of the vice president have been gathering in the streets surrounding her home since last week when a prosecutor called for a 12-year sentence for Fernández de Kirchner as well as a life-long prohibition from holding public office in the corruption case.
Shortly after the incident, government officials were quick to decry what they called an assassination attempt.
Cabinet ministers issued a news release saying they "energetically condemn the attempted homicide" of the vice president. "What happened tonight is of extreme gravity and threatens democracy, institutions and the rule of law."
Former President Mauricio Macri, a conservative who succeeded the left-of-centre Fernández in the presidency, also condemned the attack. "This very serious event demands an immediate and profound clarification by the judiciary and security forces," Macri wrote on Twitter.
Patricia Bullrich, president of the opposition Republican Proposal party, criticized President Fernández's reaction to the attack, accusing him of "playing with fire".
She said that "instead of seriously investigating a serious incident, he accuses the opposition and the press, decreeing a national holiday to mobilise activists."