Burkina Faso's armed forces say they are investigating a gruesome video that purports to show military volunteers hacking apart a dead body with machetes, while gloating to the camera.

Work is under way to verify the video and the people shown in it "so that they can be held accountable for their actions, if the facts are proven," the general staff said in a statement.

The West African nation is ruled by the military, who seized power almost three years ago promising to end the chronic insecurity that has forced two million people from their homes.

But efforts to defeat armed groups and Islamist fighters have so far failed, with an estimated 40% of the country under their control.

The video in question began circulating at the weekend.

It shows a corpse whose head and arms have been severed, and the stomach cut open.

"We beat them," one of the men in the video shouts in Burkina Faso's Dioula language. "It will all end this year. May God bless the VDP," shouts another.

VDP is short for the Volunteers for the Defence of the Fatherland.

Burkina Faso has a tradition of armed community militias for whom the government created an official role in 2020, which has since been expanded under the military government.

Some of the men in the video are wearing military fatigues, but otherwise there is no indication of their names, nor where or when the incident happened.

It is not the first time footage of alleged atrocities by government-affiliated fighters have circulated online.

Back in July, videos appeared on social media showing suspected soldiers and volunteers mutilating dead bodies, which Burkina Faso's army publicly condemned.

The county's armed forces have been accused of atrocities and extrajudicial killings.

According to Human Rights Watch, the military massacred more than 220 civilians - including at least 56 children - in a single day earlier this year.

The authorities did not comment on that report.

This latest video has provoked outrage, prompting Burkina Faso's military general staff to insist it has the nation's best interests at heart.

In its statement on Sunday, it said: "All operations to reconquer the national territory are conducted with the greatest respect for human rights."

Burkina Faso is in West Africa's Sahel region, which is considered the new global epicentre of the Islamic State group and is also home to numerous others jihadist groups.

A large deployment of Russian troops arrived in the country in January in a sign of deepening ties, a year after French troops fighting insurgents were kicked out of the country.

The junta-led Sahelian nations of Burkina, Mali and Niger have all turned to Russia for support in recent years in deals that have failed to improve security and in some cases resulted in atrocities against civilians.

At the weekend, Burkina Faso's foreign minister praised Russia and said it was a more suitable partner than the former colonial power France.

As power and influence slips away from the Sahel nations' traditional Western allies, the European Union's envoy to the region has vowed: "We have to continue to stay by their side.

"There is a reconfiguration of the region which has an impact on all of western Africa and the rest of Africa."