Communication cuts, disease outbreak in Sudan as fighting rages

War-torn Sudan's capital experienced a communications blackout for several hours on Friday, residents said, as the army and paramilitary forces waged intense battles across Khartoum and humanitarian groups warned of worsening crises.

"Violent clashes" shook the capital, witnesses told AFP over the phone, after residents woke up to an outage of vital internet and mobile phone connections.

The source of the malfunction was not clear, though mobile and internet networks were restored by the afternoon.

Throughout the day, columns of black smoke were seen rising near army headquarters in the centre of Khartoum as well as in the city's south.

Witnesses in Khartoum North said there were "clashes using all kinds of weapons". In Omdurman, just across the Nile river, witnesses reported fighter jets and drones flying overhead.

Since April 15, the forces army chief Abdel Fattah al-Burhan have been at war with the paramilitary Rapid Support Forces, commanded by his former deputy, Mohamed Hamdan Daglo.

The fighting has killed at least 3,000 people across Sudan, according to the Armed Conflict Location and Event Data Project, with the worst fighting taking place in Khartoum and the western Darfur region.

According to the United Nations, more than 1.7 million Khartoum residents have been forced to flee continuous air strikes, tanks and fighters on the streets and rampant looting.

Those who fled and the millions that remain have relied on the internet to source basic needs, setting up crowd-sourcing initiatives for escape routes, food and medicine.

- 'Life-or-death' -

More than 2.4 million people have been displaced within the country, where supplies have run low even in safe areas and "between two thirds and 80 percent of hospitals are not functioning", Rick Brennan, of the World Health Organization, said Friday.

Sudan's "already overstretched healthcare system" is facing "enormous challenges" in the current crisis, "putting the people of Sudan in a life-or-death situation," said Brennan, regional emergency director for WHO's east Mediterranean office.

In the southern city of Kosti, the last major town on the road from Khartoum to South Sudan, the Norwegian Refugee Council warned Friday that heavy rains had caused floods and "left families in need of assistance, including 260,000 who fled from Khartoum".

Aid groups have repeatedly pleaded for humanitarian corridors to allow aid and personnel through, warning that the rainy season -- which began in June -- could cause outbreaks of water-borne diseases in several remote areas.

A meeting of health workers and aid groups Thursday showed measles outbreaks in 11 of Sudan's 18 states, as well as "300 cases and 7 deaths of cholera/acute watery diarrhea", according to a statement Friday by the Islamic Relief aid group.

The water-borne disease is a regular risk with Sudan's severe annual flooding, but the WHO said Friday that "reports of a likely cholera outbreak are difficult to confirm in the absence of a functioning public health laboratory".

- Regional impact -

Sudan's neighbours -- where 740,000 people have fled, according to the UN -- fear widening regional spillover from the conflict.

In impoverished South Sudan, "the closure of the northern border has left many markets empty" and jeopardised an already fragile humanitarian situation, Pierre Dorbes of the International Committee of the Red Cross said Friday.

Since the war began, "more than 160,000 returnees and refugees from Sudan have poured into South Sudan," he said.

A summit of leaders from Sudan's neighbours met in Cairo Thursday to discuss the conflict.

Egyptian President Abdel Fattah al-Sisi urged international donors "to honour their commitments", referring to $1.5 billion in aid pledged at a Geneva conference in June -- less than half the estimated needs for Sudan and its affected neighbours.

The summit followed multiple diplomatic efforts to mediate an end to the violence, after successive US and Saudi-brokered ceasefires were all violated.

It echoed calls for a ceasefire made earlier in the week at talks held by east African bloc IGAD, which the Sudanese army had boycotted.

On Thursday, the International Criminal Court said it has commenced investigations into alleged war crimes, after increased reports of atrocities, particularly in Darfur, including of sexual violence and civilians being targeted for their ethnicity.