Khartoum: At least 56 people have been killed as Sudan's armed forces (SAF) battled the paramilitary Rapid Support Forces (RSF) for control of the country, according to the Sudanese Doctors' Union.
The doctor's syndicate also said some 600 people were wounded in the fighting that broke out on Saturday.
Fighting continued well into the night in the capital Khartoum and other parts of the country after months of tensions erupted between two rival military leaders.
The sound of heavy firing could be heard as the military urged people to remain inside their homes. Schools, banks and government offices would be closed on Sunday.
Both sides claim they control key airports and other installations.
United Nations Secretary-General Antonio Guterres spoke to the military leader Abdel-Fattah Burhan and RSF leader General Mohamed Hamdan Dagalo, calling for an immediate end to violence and a return to dialogue.
Burhan overthrew long-term ruler Omar al-Bashir in April 2019. Eighteen months later, the military and the RSF staged a second coup, upending a transition to democracy.
Disagreements between Burhan and Dagalo over the planned integration of the RSF into the regular army have now turned into open conflict.
In an interview with Qatari broadcaster Al Jazeera, Dagalo accused Burhan of starting the battle by surrounding RSF troops. "This criminal, he forced this battle upon us," he said.
Regional, international mediation needed to calm situation
Regional and international players need to step in and attempt to mediate between Sudan's generals and de-escalate the fighting, Kholood Khair, the director of the Sudan-based Confluence Advisory think tank, told DW on Sunday.
Khair said she does not expect any stepping back from the conflict "until we see… a concerted international effort at a very high level." She warned that the situation was getting "more difficult by the hour."
"Unfortunately, we haven't seen the type of political heavyweights being engaged on the mediation side," she said.
RSF leader Daglo is believed to enjoy strong ties with Gulf countries, as his forces fought in Yemen alongside the Saudi-led coalition against Houthi rebels.
Burhan is meanwhile rumored to be close to Egypt, with unconfirmed reports saying he stopped in the country hours before his 2021 coup.
Both Egypt and Saudi Arabia have called on the Arab League to convene over Sudan later on Sunday.
Khair also said the appetite for a return to a democratic path in the country was still high but stressed the violence must stop first.
"There's still a lot of support throughout the country for democratic transition," she said. "We have to remember that this power struggle between the generals is by no means indicative of the broader politics that are taking place in Sudan."
Internet reportedly blocked on government orders
Internet access was blocked in Sudan on Sunday amid the ongoing clashes between the military and the powerful RSF paramilitary.
The MTN telecommunications company blocked internet services in Sudan, following orders from the government telecommunications regulator, two MTN officials told the Reuters news agency.
Sudanese Twitter users also reported the internet outage.
Fighting 'even more aggressive,' Khartoum-based journalist says
Mohamed Amin, a journalist currently in Khartoum, told DW clashes continued on Sunday and that the situation was "even more aggressive" than Saturday with heavy shelling in the vicinity of the armed forces headquarters.
He added that there were air strikes and artillery attacks against army headquarters, with both the military and the RSF claiming control over the vital facility.
Electricity has been cut from most of the capital city, Amin said.
"The clashes can be witnessed all over Khartoum and the sounds of the bombs and gunfire are everywhere," he said. He added that Khartoum's international airport remained shuttered for the second day in a row.
RSF accused foreign planes of striking bases in Port Sudan, Amin said, describing this as a "very new element" of the conflict.