By Mohamed Noureldin
KHARTOUM (Reuters) - Sudan's war has forced 100,000 people to flee across the border and fighting now its third week is creating a humanitarian crisis, U.N. officials said on Tuesday as gunfire and explosions echoed across the capital in violation of another ceasefire.
The conflict risks morphing into a broader disaster as Sudan's poor neighbours deal with a refugee crisis and fighting blocks aid routes in a nation where two thirds of people already rely on some outside support.
"The risk is this is not just going to be a Sudan crisis, it's going to be a regional crisis," said Michael Dunford, East Africa director at the U.N. World Food Programme (WFP) .
U.N. officials said U.N. aid chief Martin Griffiths aimed to visit Sudan, possibly on Tuesday, but the timing was still to be confirmed. The WFP said on Monday it was resuming work in the safer parts of the country after a pause earlier in the conflict when some WFP staff were killed.
The leaders of the army and paramilitary Rapid Support Forces (RSF) who previously shared power show no sign of backing down, yet neither seem able to secure a quick victory, raising the spectre of a prolonged conflict that could draw in outside powers.
Early on Tuesday, black smoke could be seen hanging over the capital Khartoum, which lies on confluence of the Blue and White Nile rivers. Air strikes hit Bahri, on the east bank, while clashes flared in Omdurman to the west, witnesses said.
Hundreds of people have died in the fighting that pits the army under General Abdel-Fattah al-Burhan against the RSF under General Mohamed Hamdan Dagalo, also known as Hemedti. Each has blamed the other for the violation of a series of ceasefires.
The army has used airpower against RSF units dug into residential areas of Khartoum, damaging swathes of the capital area and reigniting conflict in Sudan's far west Darfur region.
Port Sudan, where thousands of people have fled Khartoum seeking evacuation abroad, is the main entry point for aid for many countries in the region, the WFP's Dunford told Reuters.
"Unless we stop the fighting, unless we stop now, the impact on a humanitarian scale is going to be massive," he said.
Kenya has offered the use of its airports and airstrips near the border with South Sudan as part of an international humanitarian effort, Kenyan Foreign Minister Alfred Mutua said.
Aid supplies that have arrived in Port Sudan for other aid agencies were still waiting on Monday for safe passage to Khartoum, a road journey of about 800 km (500 miles), although Medicins Sans Frontiers said delivered some aid to Khartoum.
Some 330,000 Sudanese have also been displaced inside Sudan's borders by the war, the U.N. migration agency said.
Thousands of Sudanese are also trying to exit the country, many across the borders with Egypt, Chad and South Sudan. The U.N. warned on Monday that 800,000 people could eventually leave including refugees living in Sudan temporarily.
At the border with Egypt, where more than 40,000 people have crossed over the past two weeks, delays are causing refugees to wait for days before being let through after paying hundreds of dollars to make the journey north from Khartoum.
Foreign countries have carried out their own evacuation effort, with an airlift from outside the capital and long road convoys to Port Sudan where ships have ferried them abroad.
Most European countries have ended their evacuation efforts. Russia sid on Tuesday it had pulled out 200 of its citizens.
The army and RSF had shared power since a 2021 coup but had fallen out over the timeline for a transition to civilian rule and moves to merge the RSF into the regular military.
The two had fought side by side to battle Sudan's uprising in Darfur from 2003 onwards in which more than 300,000 people died raising accusations of genocide.
(Additional reporting by Nafisa Eltahir in Cairo, Emma Farge and Gabrielle Tétrault-Farber in Geneva, Duncan Miriri in Nairobi and Ayenat Mersie in Dollow, Somalia; Writing by Angus McDowall; Editing by Edmund Blair)