Thousands of people have been forced to flee the Sudanese region of West Dafur amid fears of ethnic cleansing, a medical charity says.
Witnesses have accused the paramilitary group Rapid Support Forces (RSF) of targeting and killing non-Arabs.
This comes after the RSF captured the Sudanese army headquarters in West Darfur’s capital of El Geneina in recent days.
The RSF said it is not involved in what it described as a “tribal conflict”.
It has been battling the army for control of the country since April.
Medecins Sans Frontieres (MSF) says that most of the 7,000 people who have crossed into Chad in the past three days are women and children who are fleeing with nothing.
Since the capture of El Geneina, the RSF and allied Arab militias have been accused of murdering thousands of ethnic Masalit people, looting homes and raping women, according to Reuters news agency.
The RSF originated in Darfur and has been accused of atrocities against non-Arabic groups in the region during this year’s conflict.
The paramilitary group has been gaining more territory in Darfur since the beginning of this month, taking control of four of the region’s five states.
Peace talks in Saudi Arabia have been unfruitful as efforts to secure a ceasefire have failed, according to Reuters.
The UN refugee agency says “an unimaginable” humanitarian crisis is unfolding in Sudan.
Nearly six million people have been forced from their homes since the war began.