US Secretary of State Antony Blinken urges the military and rival paramilitary RSF to ‘stop this conflict now’.

The US also found that the RSF and their allied militias committed crimes against humanity and ethnic cleansing, Blinken said in a statement on Wednesday.

“The expansion of the needless conflict between RSF and the SAF has caused grievous human suffering,” Blinken said.

He urged both sides to “stop this conflict now, comply with their obligations under international humanitarian and human rights law, and hold accountable those responsible for atrocities.”

The RSF has been accused of orchestrating an ethnic massacre in West Darfur, 20 years after the region was the site of a genocidal campaign.

In the capital, Khartoum, residents have accused the paramilitary of rape, looting and imprisoning civilians.

Meanwhile, the army’s air and artillery attacks on residential neighbourhoods where the RSF has strongholds could be considered violations of international law, according to experts.

Residents, experts and aid groups have told Al Jazeera of growing fears that the next major battle in Sudan’s civil war could spiral into an all-out ethnic war.

While the US’s conclusion comes after a lengthy legal process and analysis, it does not carry any punitive measures. The US has imposed several rounds of sanctions since the war broke out in mid-April, however.

The war, which has killed more than 10,000 people and displaced another 6.5 million, broke out over disagreements about plans for a political transition and the integration of the RSF into the army, four years after former ruler Omar al-Bashir was deposed in an uprising.

Countless rounds of US-and-Saudi brokered peace talks have failed over the last few months.