Vandals in central France attacked a sculpture of an Algerian military hero who resisted France's colonisation of the North African country, just hours before it was inaugurated Saturday as a symbol of Franco-Algerian reconciliation.

The lower part of the steel sculpture in the town of Amboise, where Emir Abdelkader was imprisoned from 1848 to 1852, was badly damaged in the attack which comes in the midst of an election campaign dominated by harsh rhetoric on immigration and Islam.

French President Emmanuel Macron said in a statement: "Let us remember what unites us. The Republic will not erase any trace or name from its history. It will not forget any of its works. It will not tear down any statues."

Meanwhile Interior Minister Gerald Darmanin, speaking at the Paris launch of he Forum of Islam in France, condemned the "profoundly stupid" act.

Amboise mayor Thierry Boutard said he was "ashamed" of those responsible and decided to proceed with the inauguration ceremony regardless.

Police said no one had claimed responsibility for the vandalism.

The sculpture was commissioned to coincide with the 60th anniversary of Algeria's independence from France, won after a brutal eight-year liberation war that continues to poison relations between the two countries.

It was proposed by historian Benjamin Stora, who was tasked by President Macron with coming up with ways to heal the memories of the war and 132 years of French rule in Algeria.

The silhouette of the Islamic-scholar-turned-military-leader, who resisted French rule but was later feted as a hero in France for his defence of Christians in the Middle East, looks across the Loire river at the castle where he was imprisoned.

Amboise police said they were investigating the incident, which comes two months ahead of a presidential election in which an upstart far-right candidate, Eric Zemmour, has repeatedly grabbed headlines with a campaign bashing Islam and immigration from Africa, including Algeria.

The sculpture of Algerian resistance hero Emir Abdelkader was vandalised just hours before its inauguration
The sculpture of Algerian resistance hero Emir Abdelkader was vandalised just hours before its inauguration AFP / Guillaume Souvant

Algeria's ambassador to France Mohamed Antar Daoud, who attended the inauguration, condemned the attack as an act of "unspeakable baseness".

"We have to get beyond that," he said, adding that attempts to mend fences between France and Algeria would continue because "there is momentum and a desire on both sides to move forward."

The artist Michel Audiard spoke of his sorrow at seeing his work partly destroyed, calling it an intolerant "act of cowardice".

Ouassila Soum, a 37-year-old French woman of Algerian heritage who also attended the inauguration, said the vandalism left her "with a knot in my stomach".

"It's a shame and yet it's not surprising with the rhetoric of hate and the nauseating current atmosphere," said Soum, hailing the sculpture as "a symbol of the reconciliation between peoples and civilisations".

Seen as one of France's worst enemies in the late 19th century, Emir Abdelkader is considered one of the founders of modern-day Algeria for his role in mobilising resistance to French rule.

The rebellion he led failed however and he surrendered to French forces who shipped him to France, where he and his family spent four years under guard in Amboise castle.

He later moved to Syria where he won international acclaim for defending Christians during sectarian attacks.

He was awarded the Legion of Honour, France's highest award for his role in trying to end the persecution.

Stora, the historian behind the idea of the sculpture of Abdelkader, condemned the "ignorance" of those who vandalised it.

"Emir Abdelkader had several lives. He fought France but he was also a friend of France. Those who committed this act know nothing about French history," he told AFP.