Fighting between forces loyal to rival generals has raged in Sudan for a fifth day after an internationally brokered truce fell apart.

The UN said the death toll during clashes between the armed forces and a paramilitary group has risen to at least 270 since the violence erupted over the weekend.

Sustained gunfire, artillery attacks and air strikes rocked the capital Khartoum and the city of Omdurman across the Nile River.

Smoke rises over the horizon as a fire burns after a strike in Khartoum (AP)

Residents reported clashes around the military headquarters and near the international airport.

Tahani Abass, a prominent rights advocate who lives close to the military headquarters, said: “The battles intensified in the morning after sporadic gunfire over the night.”

A 24-hour ceasefire was to have been in effect from sundown Tuesday to sundown on Wednesday, with both sides pledging publicly to abide by it after US secretary of state Antony Blinken spoke to both generals.

Their failure to pause fighting for even a day, despite high-level diplomatic pressure, suggests they remain bent on pursuing a military victory, and raises the potential for a prolonged conflict.

Sudanese in the capital and in other cities have been hiding in their homes, caught in the crossfire as rival forces pounded residential areas with artillery and airstrikes and engaged in gun battles outside.

A deserted avenue is seen in Khartoum, with many residents staying at home as gun battles rage in the streets (AP)

The director-general of the UN’s World Health Organisation, Tedros Ghebreyesus, said at least 270 people have been killed and more than 2,600 wounded since fighting began on Saturday, without offering a breakdown of civilians and combatants killed.

The Sudan Doctors’ Syndicate, which monitors casualties, said on Tuesday that at least 174 civilians have been killed and hundreds wounded.

But the toll is believed to be much higher as bodies in the street have been unreachable because of ongoing fighting.

Dozens of health care facilities close to the clashes in Khartoum and in hot spots across the country stopped functioning, either because they were damaged or had to be evacuated for safety reasons.

Damaged fighter aircraft at Merowe airbase, north of Khartoum (Maxar Technologies via AP)

The conflict between the armed forces, led by Gen Abdel Fattah Burhan, and a paramilitary group known as the Rapid Support Forces, led by Gen Mohammed Hamdan Dagalo, has once again derailed Sudan’s transition to democratic rule after decades of dictatorship and civil war.

Pro-democracy groups and political parties had recently reached an agreement with the two generals – who jointly led a 2021 coup – but it was never signed and is now in tatters.

The latest push for a ceasefire was led by Mr Blinken, who spoke separately to the two generals earlier this week.

Egypt, which backs the Sudanese military, and Saudi Arabia and the United Arab Emirates, which have close ties to the RSF, have also been calling on all sides to stand down.

Shuttered shops in the capital (AP)

Mr Blinken had described the proposed one-day humanitarian ceasefire, which was to have begun on Tuesday evening, as a building block for a longer truce and a return to eventual negotiations.

However, fighting continued after the intended start of the truce and through the night.

Each side already has tens of thousands of troops distributed around Khartoum and the city of Omdurman on the opposite bank of the Nile River.

Residents had hoped for a halt long enough at least to get supplies or move to safer areas.

The fighting erupted suddenly at the start of the last week of the Islamic holy month of fasting, Ramadan.

The International Airport in Khartoum (Maheen S via AP)

Videos posted online on Tuesday showed Souq al-Bahri, a large outdoor market in northern Khartoum, in flames from nearby clashes.

Satellite images from Maxar Technologies taken Monday showed damage across Khartoum, including to security service buildings. Tanks stood guard at a bridge over the White Nile River and other locations.

The fighting is the latest chapter in Sudan’s turmoil since a popular uprising four years ago helped depose long-time autocrat Omar al-Bashir.

Gen Burhan and Gen Dagalo jointly orchestrated an October 2021 coup, derailing efforts to enshrine a civilian government.

Both generals have a long history of human rights abuses, and their forces have cracked down on pro-democracy activists.

Under international pressure, Gen Burhan and Gen Dagalo recently agreed to a framework agreement with political parties and pro-democracy groups.

But the signing was repeatedly delayed as tensions rose over the integration of the RSF into the armed forces and the future chain of command – tensions that exploded into violence on Saturday.