Sudan's warring factions fought heavy clashes in parts of the city of Bahri on Friday, residents said, a day after both sides welcomed a new mediation effort that seeks to end the three-month conflict.
The fighting that broke out on April 15 has driven civilians out of the wider capital region — consisting of the cities of Khartoum, Bahri and Omdurman — and triggered ethnically motivated attacks in the Darfur region.
Regional and international mediation efforts have so far failed to end the fighting, and U.N. officials have said Sudan could slide into civil war.
The latest mediation attempt was launched Thursday in Egypt. Both the army, which has close ties to Egypt, and the RSF paramilitary group welcomed the effort.
But four residents of northern Bahri told Reuters they awoke to heavy early morning clashes between the two sides, apparently centered near the Halfaya bridge.
While the RSF quickly fanned out across the capital in the early days of the conflict, the army has focused on air and artillery strikes that have done little to change the scene.
The army has conducted more ground operations in recent weeks, particularly in Omdurman.
The Bahri residents said they heard air strikes, artillery fire and gunshots, continuing into the afternoon.
An army source said the army had succeeded in pushing the RSF out of neighborhoods in the far north of the city in the morning, but the RSF said in a statement they were able to defeat the forces and claimed to kill hundreds.
the Sudanese army said in a statement that it had launched ground operations in all three cities of the capital and that it had been successful, acknowledging some losses in Bahri but calling the RSF number inflated.
Residents of the wider capital area reported a communications outage for several hours in the morning.
Other eyewitnesses reported clashes around an army base in southern Khartoum as well.
On Friday, Sudanese human rights organizations said they had evidence the RSF had detained more than 5,000 people in the capital and were keeping them in inhumane conditions.
When asked for comment, the RSF said the reports were incorrect, and that it only held prisoners of war who were well-treated.
"These organizations are ignoring violations by the army against civilians, including air and artillery strikes, detentions and arming of civilians," a representative for the force said.
Among those detained in several locations across Khartoum were combatants, but also 3,500 civilians, including vulnerable women and foreign nationals, said the organizations, who asked to have their names withheld for fear of retribution.
They said they would present to the United Nations documentation of cases of death by torture, as well as "degrading, inhumane conditions of detention devoid of human dignity and the most basic necessities of life."
The U.N. human rights office said on Thursday at least 87 people had been buried in a mass grave in the Darfur city of El Geneina, accusing the RSF and allied militias of the killings, which the paramilitary force denied.
Late on Thursday, the International Criminal Court said it would investigate killings across the region. The RSF did not respond to a request for comment on the investigation.