Argentina's Vice President Cristina Fernandez de Kirchner was attacked late on Thursday by an assailant with a loaded gun that apparently failed to discharge.

The attack happened outside her Buenos Aires home where hundreds of supporters have gathered in recent days to voice their backing for the former two-term president. She is facing corruption allegations that she denies, with prosecutors calling for a lengthy jail term.

WHO IS THE SUSPECTED ATTACKER?

A suspect was arrested who has been named by federal police as Fernando Andres Sabag Montiel, a 35-year-old Brazilian, who had previously been cited for possession of a knife last year.

Local newspaper La Nacion, citing police sources, said that Montiel had been working as a driver and renting rooms in the Villa Zagala neighborhood of Buenos Aires. Police found 100 bullets when they raided the property, the newspaper said.

The owner of the property where Montiel was renting, Sergio Paroldi, told La Nacion that Montiel had appeared normal.

"He didn't seem crazy in the slightest. He was always very polite. He called me 'Sir', always with respect," he said.

Fernandez de Kirchner has long been a divisive figure in Argentina, but police have not given a possible motive for the attack.

HOW DID THE ATTACK TAKE PLACE?

The attack happened around 9pm local time (0000 GMT) on Thursday as Fernandez de Kirchner was arriving back at her home, police said. Police said five people had chased the suspect, accusing him of attempting to kill the vice president.

Federal police forces quickly arrested the suspect, identifying him as Montiel.

The attacker used an Argentine-made 32-caliber Bersa 380 pistol, according to police. President Alberto Fernandez said that the gun had been loaded.

"A man pointed a gun at her head and fired. Cristina's alive for a technical reason as yet unclear. The gun, which had five bullets in it, did not go off even though the trigger was pulled," President Fernandez said.

WHAT ABOUT SECURITY?

The vice president was surrounded by security personnel, but interacting closely with crowds of supporters who have daily gathered near her home. The attacker was able to push through the crowd, getting within feet of Fernandez de Kirchner and waving the gun in her face, video of the incident shows.

Miguel Angel Pichetto, a prominent lawmaker, called for a probe into how the attacker was able to approach.

"There needs to be an investigation into how this subject got so close. What happened to her security?" Pichetto said to local television station TN.

"You have to evaluate why she was so alone at that moment, that the person could get almost face to face."