Sudan’s western region of Darfur is experiencing escalating violence in the civil war, which has struck two cities in the vast desert region formerly seen as relative safe havens from the conflict.
The worsening crisis in Darfur has already led to allegations of massacres committed by the Rapid Support Forces, led by Gen Mohamed Dagalo, who are fighting the regular army led by Gen Abdel Fattah Al Burhan.
Fighting has reached the city of El Fasher, witnesses said, with the sound of heavy weapons heard overnight in the city of about 250,000. Its population is thought to have swelled as millions in the country fled the April 15 eruption of violence in the capital, Khartoum, which has spread across the country and killed at least 5,000.
Darfur was the scene of genocidal violence in the early part of this century, when as many as 300,000 were killed in ethnic clashes, mostly at the hands of a government-linked militia, the Janjaweed. The group now fights as the RSF.
"This is the biggest gathering of civilians displaced in Darfur, with 600,000 people in El Fasher," said Nathaniel Raymond of the Humanitarian Research Lab at the Yale School of Public Health.
Witnesses also reported fighting in Al Fulah, the capital of West Kordofan state, which borders North Darfur.
Numerous rights groups and witnesses who fled Darfur reported the massacre of civilians and ethnically driven attacks and killings, largely by paramilitary forces and their allied Arab tribal militias.
Many have fled across the western border to neighbouring Chad, while others have sought refuge in other parts of Darfur, where the International Criminal Court is looking into allegations of war crimes.
Farther east, a resident of Al Fulah said "the RSF are confronting the army and the police, and public buildings have been set on fire during their fire exchanges".
"Shops were looted and there are dead on both sides, but no one can get to the bodies in this chaos," another witness in Al Fulah said.
The conflict has displaced about four million Sudanese, according to UN figures.