Clashes flared in parts of Sudan on the 100th day of the war on Sunday as mediation attempts by regional and international powers failed to find a path out of an increasingly intractable conflict.

The fighting broke out on April 15 as the army and paramilitary Rapid Support Forces (RSF) vied for power. Since then, more than 3 million people have been uprooted, including more than 700,000 who have fled to neighbouring countries.

Some 1,136 people have been killed, according to the health ministry, though officials believe the number is higher.

Neither the army nor the RSF has been able to claim victory, with the RSF's domination on the ground in the capital Khartoum up against the army's air and artillery firepower.

Infrastructure and government in the capital have fallen apart while fighting has spread westwards, particularly to the fragile Darfur region, as well as to the south, where the rebel SPLM-N group has tried to gain territory.

Over the weekend, the RSF moved into villages in Gezira State directly south of Khartoum, where the army conducted air strikes against them, according to witnesses.

In Nyala, one of the country's largest cities and capital of South Darfur, clashes have continued since Thursday in residential areas, according to witnesses. At least 20 people have been killed, medical sources said. The United Nations says 5,000 families have been displaced, and residents have reported looting of key facilities.

"Bullets are flying into homes. We are terrified and no one is protecting us," said 35-year-old Salah Abdallah.

The fighting gave way to ethnically targeted attacks by Arab militias and the RSF in West Darfur, from which hundreds of thousands of people have fled to Chad.

Residents have also accused RSF soldiers of looting and occupying wide swathes of the capital. The RSF has said it would investigate.

Late on Sunday, the Sudanese army said nine people died, including four military personnel, when a civilian Antonov plane crashed due to a technical failure at Port Sudan airport in the east of the country. A young girl survived the accident, the army added in a statement.

While the two warring sides have shown openness towards mediation efforts led by regional and international actors, none has resulted in a sustained ceasefire.

Both sides have sent delegations to attempt to re-start talks in Jeddah that have yielded often-violated ceasefires.

But the Sudanese foreign minister said on Friday that indirect talks had not begun seriously.

The leaders of the army and RSF headed a joint council since the ouster of former ruler Omar al-Bashir in 2019 and diverged over plans for a transition to democracy.

Civilian political groups as well as the RSF have accused the army of turning a blind eye to appearances by wanted Bashir loyalists in recent days.

The Forces of Freedom and Change, the main civilian coalition, said on Sunday it was holding meeting in Egypt, which offered itself as a mediator in the conflict.