Demo banner reveals security 'flaws' at Eiffel Tower

Activists strung up a banner in protest at the programme of far-right presidential candidate Marine Le Pen

Paris police said Friday the fact Greenpeace activists were able to hang a giant banner on the Eiffel Tower revealed "flaws" in the monument's security at a time when terror fears remain high, Paris police said.

Though security has been boosted around French tourism sites, the activists strung up a banner saying "Liberty, Equality, Fraternity" and "#resist" in protest at the programme of far-right presidential candidate Marine Le Pen.

Police said after the incident -- which comes two days before France votes in a divisive run-off -- they had called a meeting with city officials and the company operating the monument to "assess the facts, learn and adapt". The incident revealed "flaws in the monument's security programme," Paris police said in a statement.

France is on high alert after a string of militant attacks in the past two years that have killed over 230 people. Twelve people were arrested over the stunt in which a safety net was also damaged.

The activists hung the banner from an arch connecting two legs of the iconic 324-metre (1,063-foot) Iron Lady, the symbol of Paris.

Paris officials announced in February plans to protect visitors by erecting bulletproof glass walls at the northern and southern ends of the monument area.

The glass walls are intended to prevent individuals or vehicles storming the site visited by six million people each year, making it the world's most visited paying monument.

Greenpeace France head Jean-Francois Julliard told reporters the protest was intended as "a warning against Marine Le Pen's programme and the dangers it poses for NGOs and others."

"Liberty, equality, fraternity: it is vital to defend these values which are particularly threatened by the National Front," Julliard said, referring to Le Pen's party.

Julliard said Greenpeace was concerned about the "resurgence of nationalism" around the world, citing Turkey and Hungary as examples of countries where the right to protest had been curtailed.

Defending basic rights "is critical to continuing our environmental struggle," he added.

Le Pen faces centrist Emmanuel Macron in Sunday's presidential run-off. Polls give him a lead of 22-24 points.