Secretary of State Antony Blinken on Wednesday announced his determination that combatants on both sides of Sudan’s ongoing civil conflict have committed war crimes in recent months, and that some had also committed crimes against humanity and ethnic cleansing.

Since mid-April, members of the Sudanese Armed Forces (SAF) and the Rapid Support Forces (RSF) militia have been locked in violence. In his statement, Blinken said these groups have both “unleashed horrific violence, death, and destruction across Sudan,” adding that “civilians have borne the brunt of this needless conflict.” He said that both groups were responsible for war crimes, and accused the RSF and its affiliated belligerents of crimes against humanity and ethnic cleansing.

The RSF grew out of the Janjaweed militia, a group whose scorched earth tactics in Darfur led to accusations of genocide, including by then-US Secretary of State Colin Powell. Blinken nodded to this parallel in his statement Wednesday: “In haunting echoes of the genocide that began almost 20 years ago in Darfur, we have seen an explosion of targeted violence against some of the same survivors’ communities.”

The designation aimed to provide “force and renewed urgency” to resolving the conflict, the secretary said. In a statement, Amnesty International USA’s Africa advocacy lead Kate Hixon lauded the secretary’s determination, but urged officials to take meaningful action. “Releasing the atrocity determination is only the first step towards justice and accountability for the Sudanese people. This determination must be followed by concrete policy action including further support for Sudanese human rights defenders documenting violations, supporting the Human Rights Council’s Fact Finding Mission for Sudan, enforcing the existing UN Security Council arms embargo on Darfur, and expanding the arms embargo to cover the entirety of Sudan,” Hixon said.