The number of people uprooted by a conflict between military factions in Sudan that erupted nearly three months ago has surpassed 3-million, according to estimates from the International Organization for Migration.

More than 2.4-million people have been displaced internally and more than 730 000 have crossed into neighbouring countries, data published late on Tuesday said.

Most have fled either from the capital Khartoum, the focus of the power struggle between the army and the paramilitary Rapid Support Forces (RSF) that broke out on April 15, or from Darfur, where ethnically-targeted violence has surged.

On Wednesday, residents reported the sound of fighter jets and artillery shelling in Omdurman and Bahri, parts of the wider capital.

Fighting has also been reported in recent days between the army and powerful SPLM rebel factions in South Kordofan State, and in Blue Nile State near the border with Ethiopia, triggering displacement from those regions as well.

The fighting has laid waste to large parts of the capital and led to waves of attacks in Darfur. Civilians have faced widespread looting, power cuts, food and water shortages, a collapse in health services and a spike in sexual violence.

The Sudanese government's Combating Violence against Women and Children unit said on Tuesday it had recorded nine new cases of sexual assault in Khartoum, bringing the total since mid-April to 51, adding that the real number of cases was likely much higher.

Most victims blamed RSF forces for the assaults, the unit, which is seen as impartial, said in a statement. The RSF has called on civilians to report violations and said members found to be involved in abuses will be held to account.

Of those leaving Sudan, the majority have fled north to Egypt or west to Chad, with large numbers also crossing into South Sudan and Ethiopia.

After sharing power with civilians following the overthrow of Omar al-Bashir during a popular uprising four years ago, the army and the RSF seized full control in a coup in 2021 then came to blows amid disputes over a plan for a transition towards elections.

International efforts to broker an end to the fighting have shown little sign of progress, including talks led by Saudi Arabia and the United States in Jeddah that were adjourned last month, and an African-led meeting in Addis Ababa this week.

A summit of Sudan's neighbours will be held in Cairo on Thursday.