Growing violence in the country of Mali has claimed the lives of hundreds of civilians who were killed last week by Malian soldiers, the New York Times reports.

Although reports about the actual numbers are still unclear, it’s estimated that between 200 and 400 people had been killed in the town of Moura.

Reportedly, hundreds more were killed last month by Islamist insurgents, according to the group Human Rights Watch, which described it as “the worst atrocity in Mali’s decade-long armed conflict."

Over the past decade, Mali’s military has fought against Islamist insurgents and other extremist groups in the Sahel region. As a result of the violent encounters, hundreds of civilians have been killed and thousands more have been displaced.

For nine years, the French have joined Malian forces in the conflict but France announced the ending of its counterterrorism operation earlier this year.

According to reports, Malian security forces have contracted Russian mercenaries through the Wagner Group, a private military company for armed assistance.

While both Malian and Russian officials deny military arrangement, French sources suggest that about 1,000 Russian mercenaries are currently stationed in Mali.

Corinne Dufka, a director of Human Rights Watch in West Africa, spoke to more than 15 residents of the town and said that helicopters attacked Moura back on March 27, while hundreds of people were gathered at the weekly livestock market. Also, she said the Malian forces were assisted by Russians and that they held cities hostage for four days, opening fire on the market.

When Colonel Souleymane Dembélé, the head of the Malian armed forces’ communication unit was contacted by phone about the allegations, he had “no reaction."

Dufka also said that during the attack, jihadist fighters were present in the village, which is a stronghold of the Macina Liberation Front, an affiliate of Al Qaeda.

“Executing civilians and suspects in the name of security is as unlawful as it is counterproductive,” she said. “ It is driving recruitment into abusive groups, stoking intercommunal tension and undermining trust in the state.”

Ned Price, a department spokesperson for the U.S. State Department called the event a “reported massacre” in a statement on Sunday.

 “We are concerned that many reports suggest that the perpetrators were unaccountable forces from the Kremlin-backed Wagner Group,” the statement read.

Yvan Guichaoua, a senior lecturer on international conflict at the University of Kent who specializes in the Sahel region, noted that Malian forces had a long history of abuses and the abuse have increased this year.

“That uptick coincides with the arrival of Russian forces,” Guichaoua said. “The frequency and the scale of these attacks are unprecedented.”