The video, filmed with a drone and seen by AFP on Thursday, shows what appear to be Caucasian soldiers covering bodies with sand near the Gossi base in northern Mali.

It came after a Twitter account using the name Dia Diarra, who describes himself as a "former soldier" and "Malian patriot", posted images of pixelated corpses buried in sand and accused France of atrocities.

"This is what the French left behind them when they left the base in #Gossi... We cannot keep silent!" the account wrote.

France's general staff called the Twitter video an "information attack" and said the profile was "very probably a fake account created by Wagner", a private Russian mercenary group.

France's army said comparing the photos published on Twitter against images taken by a special sensor allows them to "draw a direct line" between Wagner's activities and what has been falsely attributed to French soldiers.

"This manoeuvre to discredit the Barkhane force seems coordinated. It is representative of multiple information attacks French soldiers have faced for several months," it said.

France and the United States have accused Wagner mercenaries of deploying in Mali as Paris winds down its almost decade-long military operation in the West African country, Barkhane.

Mali's military-dominated government has denied the accusations and said the Russians in the country are military instructors.

France officially handed control of the Gossi base to the Malian army on Tuesday as part of its withdrawal announced in February.

The French general staff warned about information warfare following the retrocession of the base, which hosted 300 French soldiers.

Spokesman Pascal Ianni said a report had been compiled establishing the state of play to protect France against potential accusations, including arming terrorists and committing exactions.

Anti-French sentiment has grown in West Africa, where French forces have operated since 2013 to stem jihadist insurgencies, and social media campaigns have targeted French troops.

France's pull-out from Mali came as swathes of territory remained under the control of rebels linked to Al-Qaeda and the Islamic State group and as tensions spiked between Paris and Bamako over the alleged deployment of Wagner mercenaries.