What happened today in France's presidential race

Elite police and intelligence agents carried out the arrests in Marseille

Just days before voting begins in France's presidential election, police arrested two men suspected of plotting an attack, the race drew ever tighter and holograms made a comeback.

Here's what happened in the campaign on Tuesday:

- Attack plot thwarted -

An attack plot foiled by authorities in southern France sparked fears the closing days of the campaign could be a target for extremists.

The plan unravelled when police arrested two Frenchmen in Marseille that authorities said were "radicalised" and seized bomb-making materials as well as guns.

"They were aiming to commit in the very short term, in other words in the next few days, an attack on French soil," Interior Minister Matthias Fekl said.

Last week, photos of the two suspects in the attack plot were distributed to the security teams for far-right candidate Marine Le Pen and centrist Emmanuel Macron.

"The fact that these two individuals were arrested in Marseille when Marine Le Pen is holding a rally there the next day is perhaps not a coincidence," a source from the Le Pen camp told AFP.

Authorities have not said if any of the candidates were targeted by the plotters.

- Closing in on frontrunners -

On the campaign trail, the race was narrowing ahead of Sunday's vote, with the pack closing behind frontrunners Macron and Le Pen.

For weeks, centrist former banker Macron and National Front (FN) leader Le Pen have been out in front but opinion polls now show any of the four leading candidates could reach the second-round run-off on May 7.

Scandal-plagued conservative Francois Fillon and far-left firebrand Jean-Luc Melenchon have closed the gap dramatically in the last two weeks.

"We have never seen a four-way contest like this in the first round of a presidential election," Frederic Dabi of the Ifop polling institute told AFP.

- Seven places at once -

Hard-left candidate Melenchon was set to again broadcast himself via hologram to cheering supporters across mainland France -- and even a bit further.

He got so much attention for beaming his likeness from one rally -- where he appeared in person -- to another some 450 kilometres (280 miles) away in February, that he planned to do it again Tuesday night.

However, this time his campaign went much bigger with plans to speak to a crowd in the eastern city of Dijon and to pipe him in to Montpellier, Grenoble, Nancy, Nantes, Clermont-Ferrand and even France's Reunion island in the Indian Ocean.

"It's his last big speech and so it will be something energetic that brings some momentum for the end of the campaign and beyond," said Charlotte Girard of La France Insoumise (Unbowed France), Melenchon's political movement.