An increasing number of Sudanese civilians fleeing El Geneina, a city in Darfur hit by repeated militia attacks, have been killed or shot at as they tried to escape by foot to Chad since last week, witnesses said.

The violence in El Geneina over the past two months has been driven by militias from Arab nomadic tribes along with members of the Rapid Support Forces RSF, a military faction engaged in a power struggle with Sudan’s army in the capital, Khartoum, witnesses and activists said.

Medical charity MSF said 15,000 people had fled West Darfur over the previous four days, and it said many arrivals reported seeing people shot and killed as they tried to escape El Geneina, MSF also reported rapes.

The war that erupted in April has uprooted more than 2.5million people, according to United Nations estimates, mainly from the capital and from Darfur, which was already suffering from two decades of conflict and mass displacement.

Nearly 600,000 people have crossed into neighboring countries, including more than 155,000 who have fled Darfur for Chad.

A 72-hour cease-fire, brokered by Saudi Arabia and the United States and due to expire early on Wednesday morning, has brought a lull in fighting in Khartoum, though residents report looting has spread, and the army said the RSF had caused a huge fire at the intelligence headquarters.