More than one million people have fled Sudan to neighbouring states and people inside the country are running out of food and dying due to lack of healthcare after four months of war, the United Nations warned on Tuesday.

Fighting between the Sudanese army and the paramilitary Rapid Support Forces (RSF) has devastated the capital Khartoum and sparked ethnically-driven attacks in Darfur, threatening to plunge Sudan into a protracted civil war and destabilise the region.

"Time is running out for farmers to plant the crops that will feed them and their neighbours. Medical supplies are scarce. The situation is spiralling out of control," U.N. agencies said in a joint statement.

The war has caused 1,017,449 people to cross from Sudan into neighbouring countries, many already struggling with the impact of conflicts or economic crises, while those displaced within Sudan are estimated to number 3,433,025, according to the latest weekly figures published by the IOM.

Fighting erupted on April 15 over tensions linked to a planned transition to civilian rule, exposing civilians in the capital and beyond to daily battles and attacks.

The millions who remain in Khartoum and cities in the Darfur and Kordofan regions have faced rampant looting and long power, communications and water cuts.

"The remains of many of those killed have not been collected, identified or buried," but the U.N. estimates that more than 4,000 have been killed, Elizabeth Throssell, spokesperson for the High Commissioner for Human Rights, said in a briefing in Geneva.

Reports of sexual assaults have increased by 50%, said U.N. population fund official Laila Baker.

BLACKOUT

Large swathes of the country have been suffering from an electricity blackout since Sunday that has also taken mobile networks offline, according to a statement from the national electricity authority.

Seasonal rains that increase the risk of water-borne diseases have destroyed or damaged the homes of up to 13,500 people, the U.N. estimates.

In a speech on Monday, army chief General Abdel Fattah al-Burhan accused the RSF of aiming "to take the country back to an era before the modern state" and "committing every crime that can be imagined."

The RSF has accused the army of trying to seize full power under the direction of loyalists of Omar al-Bashir, the autocratic leader who was toppled during a popular uprising in 2019.

Efforts led by Saudi Arabia and the United States to negotiate a ceasefire in the current conflict have stalled, and humanitarian agencies have struggled to provide relief because of insecurity, looting and bureaucratic hurdles.

(Reporting by Khalid Abdelaziz in Dubai, Nafisa Eltahir in Cairo, and Gabrielle Tetrault-Farber in Geneva; Writing by Aidan Lewis, Editing by Alexandra Hudson)