France has accused Russia-based hackers of mounting an “unprecedented” cyber attack against New Caledonia as Emmanuel Macron flew out to the Pacific territory to try to quell a violent insurrection.

The cyber assault took place hours after French investigators reportedly said they suspected Moscow was involved in pro-Palestinian red hands being daubed on Paris’s Shoah memorial last week.

“Last night, we suffered a cyber attack of unprecedented force in New Caledonia, as an [internet] service provider was attacked from outside on an IP address with the aim of saturating the New Caledonian network”, said Christopher Gygès, a member of the local collegiate government.

“The majority of IP addresses” identified came from Russia, as he told BFMTV, adding that the attack was stopped “before any major damage” could occur.

“Millions of emails were sent simultaneously to an email address whose purpose was to saturate the network “and render it inoperative”, he said, dubbing the cyber attack a “provocation” ahead of Mr Macron’s arrival.

The deadliest unrest in four decades was sparked by French plans to give voting rights to thousands of non-indigenous residents, which Kanaks say will dilute their votes.

French authorities sent more than 1,000 troops, tactical police and national security reinforcements from Paris in a bid to quell the violence. 

Police have arrested more than 280 “rioters” in the French territory of 270,000, authorities said. Unrest is ongoing, however, albeit not on the scale of last week.

Mr Macron was due to arrive in the troubled French territory on Thursday, where he plans to meet with local officials and set up a “mission” with the aim of calming the situation on the archipelago after a week of riots that have left six people dead.

Despite attempts to dislodge them, Kanak separatists were reportedly manning makeshift roadblocks including on the main route to the international airport.

Armed locals, of French and other origins, have set up their own neighbourhood barricades.

The cyber attack came amid French claims of foreign meddling in New Caledonia and other overseas territories. Last week, France accused Azerbaijan of seeking to foment anti-Paris sentiment on the archipelago.

Azerbaijan swiftly denied the allegations as “baseless”.

On Wednesday, investigative French weekly Le Canard Enchaîné cited French intelligence sources blaming Russia for 20-odd red handprints daubed at the Shoah Memorial in Paris last week.

Le Canard said investigators managed to identify and track via CCTV two Bulgarian nationals behind the graffiti, along with their accomplice who filmed the scene.

Dressed in black, they can be seen tagging the Wall of the Righteous, which lists the names of the 3,900 people who risked their lives to save Jews during the Occupation.

Shortly afterwards, the investigators located their hideout, a hotel in the 20th arrondissement of Paris, where a copy of the passport of one of them was found, according to reports. Immediately after the “operation”, the three suspects boarded a coach to Brussels.

The symbolism of red hands has been the subject of controversy in France in recent weeks after students at Sciences Po Paris held up red-dyed hands in support of Palestine. 

However, critics pointed out that red hands also evoke the lynching of two Israeli reservists in Ramallah by Palestinians in October 2000, one of whom then showed his blood-covered hands to the crowd.

The vandalism is reminiscent of the case of the stars of David spray-painted on walls in several Paris districts last October. I

nvestigators found that four Moldavians behind the tags had been commissioned by a businessman reputedly close to Moscow. 

Two of the four suspects also fled Paris by taking the same FlixBus to Brussels.

France has repeatedly accused Russia of seeking to foment anti-French sentiment in Africa and more recently by amplifying panic over a bed bug invasion in France.

Russia has ratcheted up anti-French rhetoric ever since Mr Macron said he wouldn’t rule out sending ground troops to Ukraine if its defences failed.

On Wednesday,  a Russian foreign ministry official cited by Ria Novost warned that if France sends its troops to Ukraine, Russia’s response will be “not only political”.

Artyom Studennikov, the head of the European department at the ministry, did not specify which measures Russia would take in such an event, but said Moscow has warned Paris about them and added that sending French troops to Ukraine would increase the risk of a clash between two nuclear powers.