At least 15 civilians in Khartoum were killed on Saturday "when shells fell on their homes", a medical source said, as paramilitary fighters battling Sudan's army claimed gains in Darfur.
The victims' bodies were taken to Al-Nau hospital in Omdurman, a district of greater Khartoum, the medical source told AFP, speaking on condition of anonymity.
Fighting since April between the forces of army chief Abdel Fattah al-Burhan and his former deputy Mohamed Hamdan Daglo, who commands the Rapid Support Forces (RSF), has raged in heavily populated areas.
The struggle between the rival generals has crippled essential services in Sudan and razed entire neighbourhoods of the capital and the vast western region of Darfur.
In nearly seven months of war, more than 10,400 people have been killed, according to a conservative estimate from the Armed Conflict Location & Event Data Project.
The United Nations says the violence has forced more than 6 million people to flee, both within and outside Sudan.
Representatives of the warring sides are currently in the Saudi city of Jeddah for negotiations mediated by Saudi Arabia and the United States, but the fighting back home has raged unabated.
For weeks, the RSF has been advancing on army bases in Darfur, a region already scarred by decades of conflict and atrocities committed against civilians by armed groups including the RSF's predecessor, the Janjaweed militia.
On Saturday, the paramilitary force announced it had "liberated" an army base in El Geneina, the capital of West Darfur state where a communications blackout has raised fears of fresh horrors.
According to Clementine Nkweta-Salami, the UN's most senior representative in the country, reports of "civilians being caught in the ongoing fighting" in Darfur recall "the events in El Geneina" in June, when rights groups and witnesses reported massacres, rampant sexual violence and mass graves.
More than half a million people have fled the violence in Darfur to neighbouring Chad, which is just 30 kilometres (18 miles) from El Geneina.
The events in West Darfur and other reports of ethnically motivated killings by the RSF and allied militias have triggered a new investigation by the International Criminal Court into alleged war crimes and crimes against humanity.
The army base in El Geneina is the third the RSF has claimed to have captured in a week, after Zalingei, the capital of Central Darfur, and Nyala, the South Darfur state capital and the second largest city in Sudan.
US Secretary of State Antony Blinken issued an unusually strong statement on Monday, warning against signs of an "imminent large-scale attack" in El Fasher, the capital of North Darfur state.
The attack "would subject civilians, including hundreds of thousands of displaced persons -- many of whom only recently fled to El Fasher from other areas -- to extreme danger," Blinken said.
Darfur is a region the size of France, and home to a quarter of Sudan's 48 million people.
As Sudan's civilians face what UN humanitarian chief Martin Griffiths has called "one of the worst humanitarian nightmares in recent history", both sides have positioned themselves as peacemakers in the resumed negotiations in Saudi Arabia.
US officials say the goals for now are limited to allowing in humanitarian assistance and pushing for a sustainable ceasefire.
In previous negotiations, every agreed truce was almost immediately violated by both sides, and have both also been accused of obstructing, attacking or looting aid.
The RSF on Monday published a video of its commander, Daglo, who has kept mostly out of sight throughout the conflict, in which he blamed Burhan for the war and congratulated his forces for their "victory" in Darfur.
Daglo said the RSF "has no problem with peace", but it will not agree to "a ceasefire that allows the army" to regroup.
