On Friday, the Malian military said that between March 21-31 it had killed 203 combatants in an operation in the Moura area of jihadist-ridden central Mali.

However, the announcement followed social media reports this week alleging that large numbers of civilians had been killed in Moura.

AFP was unable to verify the Malian army's claimed death toll or the social media reports about civilian deaths.

Poor access to Mali's conflict areas and a relative lack of independent information sources means that figures provided by both the government and armed groups are difficult to confirm.

On Sunday, the US State Department said that it was following the "extremely disturbing accounts of large numbers of people killed" in Moura and offered its condolences to the families of "all civilians who died".

It noted in a statement that many reports suggested that operatives from Russian private military contractor Wagner had committed the killings, while others said that Malian armed forces had killed militants.

"These conflicting reports illustrate the urgent need for the Malian transition authorities to give impartial investigators free, unfettered, and safe access to the area where these tragic events unfolded".

The State Department called on Mali's army-dominated interim government to allow the UN peacekeeping mission in Mali, known as Minusma, to investigate.

Failure to investigate will sow divisions, undermine the army's credibility, and "drive communities into the hands of violent extremist groups," it added.

An impoverished nation of around 21 million people, Mali has struggled to contain a jihadist insurgency that emerged in 2012, before spreading to neighbouring Burkina Faso and Niger.

Vast swathes of the country are home to myriad rebel groups and militias, and thousands of soldiers and civilians have been killed in the conflict.

Mali's under-equipped army has often been accused of committing abuses. The United States and others also say that Russian private security firm Wagner has deployed hundreds of fighters to Mali.

Mali's interim government has repeatedly denied the claims, however, and regularly defends the record of its armed forces.

For instance, the Malian army stated Friday that it was guided by human rights and international law, calling for "restraint against defamatory speculations".

Minusma, the UN peacekeeping mission, said Saturday that it is "very concerned about the allegations of violence against civilians" in Moura.