The U.S. Treasury Department has imposed sanctions on Mohamed al-Kani and his Kaniyat militia in Libya for alleged human rights abuses.

The move came after Russia prevented the United Nations from sanctioning the group last week, Reuters said.

The Treasury Department said the Kaniyat militia killed civilians recently found in multiple mass graves in the western Libyan city of Tarhouna. Additionally, the group engaged in torture and forced disappearances, according to a statement Wednesday.

According to Treasury, the militia gained control in Tarhouna over several years while detaining, torturing and killing civilians. In 2019, it changed allegiance from Libya's internationally recognized Government of National Accord (GNA) to the Libyan National Army (LNA), giving that group a foothold near Tripoli during its offensive against the Libyan capital.

The statement said that in June 2019, after a de facto truce, GNA-aligned forces re-entered Tarhouna and discovered at least 11 mass graves containing the bodies of civilians previously detained by the Kaniyat militia, including women, children and elderly.

"Some of the deceased appeared to have been tortured, burned or buried alive," the statement said.

"Mohamed al-Kani and the Kaniyat militia have tortured and killed civilians during a cruel campaign of oppression in Libya," Treasury Secretary Steven Mnuchin said in the statement. "The United States stands with the Libyan people and will use the tools and authorities at its disposal to target human rights abusers in Libya and across the world."

Those sanctioned will be blocked from accessing property interests in the U.S.