The Sudanese civil aviation authority has extended the closure of Sudan's airspace until August 15, except for humanitarian aid and evacuation flights, Khartoum International Airport said early on Monday.
Sudanese airspace has been closed to regular traffic since a military conflict erupted between the country's army and the paramilitary Rapid Support Forces in mid-April.
Khartoum International Airport has been making exceptions for humanitarian and evacuation flights, subject to the right permits being obtained by relevant authorities.
The RSF has ordered civilians to evacuate homes in the capital's south, several residents said on Sunday as fighting between the forces of rival generals raged in the western Darfur region.
“Members of the RSF told me I had 24 hours to leave the area,” Khartoum resident Fawzy Radwan told AFP.
He had been guarding his family's home since fighting began in the city.
The war between army chief Gen Abdel Fattah Al Burhan and his former deputy, RSF commander Gen Mohamed Dagalo, has killed at least 3,900 people, according to a conservative estimate, and displaced around 3.5 million.
Much of the fighting has occurred in densely populated neighbourhoods of Khartoum, causing 1.7 million residents to flee and forcing the millions who remain to shelter from the violence in their homes, rationing water and electricity.
Hundreds of residents were being evicted from southern Khartoum's Jabra neighbourhood on Sunday, residents said.
Jabra and nearby Sahafa are home to the army artillery corps as well as an RSF base used by Gen Dagalo.
Along with Khartoum, some of the worst violence is being witnessed in the conflict-scarred region of Darfur, where allegations of war crimes by the RSF have sparked a new investigation by the International Criminal Court.
Clashes on Sunday in the town of Nyala – the capital of South Darfur state and Sudan's second biggest city – sent bombs falling on civilian neighbourhoods, witnesses said.
Over 2.6 million people have been displaced within Sudan since the war began, and more than 800,000 others have fled across borders.