Smoke billows in the distance in Khartoum on Monday, as fighting between two rival generals persists. AFP

They reported combat in north Khartoum, and air strikes in the east of the capital shortly after 9:45 pm (1945 GMT) Monday night when the truce was to take effect, with the smell of smoke still lingering after gunfire and explosions rocked the city throughout the day.

The ongoing fighting dampened hopes for a pause to allow in humanitarian aid or let residents flee.

READ MORE

Fire razes school dormitory in Guyana kills at least 20 children

Russia claims to have Bakhmut but Ukraine says the battle is not over

A series of previous truce deals were all violated.

"Beyond official announcements, Sudan is still pounded and bombarded, with millions of civilian lives at risk," Karl Schembri of the Norwegian Refugee Council wrote on Twitter.

"We've had over a month of broken promises and empty words while humanitarian colleagues were killed, together with children and others and hospitals destroyed."

Armed men walk in Khartoum on Monday, as fighting between two rival generals persists. AFP

Since April 15, fighting between the army, led by Sudan's de facto leader Abdel Fattah al-Burhan, and the paramilitary Rapid Support Forces commanded by Burhan's former deputy Mohamed Hamdan Daglo, has left about 1,000 people dead and forced more than a million to flee their homes.

Earlier on Monday, residents of the capital -- anxious for a reprieve to enable them to reach stranded relatives, flee to safety or get access to humanitarian assistance -- said there was little to show fighters were preparing to pause, reporting air strikes and anti-aircraft fire for the 37th consecutive day.

"Fighter jets are bombing our neighbourhood," Khartoum resident Mahmoud Salah el-Din told AFP, in the hours before the truce was to take effect.

While no previous truce has held, the United States and Saudi Arabia -- which brokered the deal -- said this one was different because it was "signed by the parties" and would be supported by a "ceasefire monitoring mechanism".

A bus carrying people fleeing the ongoing fighting drives down a road in southern Khartoum on Sunday. AFP

Air strikes and gunfire have usually quietened down overnight during the war, which has now lasted more than five weeks.

According to the seven-page agreement released by the United States, warring sides were to use the two days before it took effect Monday night to "inform their respective forces" about it and "instruct them to comply".

But Volker Perthes, the UN's envoy to Sudan, told the United Nations Security Council that "fighting and troop movements have continued even today, despite a commitment by both sides not to pursue military advantage before the ceasefire takes effect".

While government forces control the skies, they have few men on the ground in the centre of Khartoum, where RSF are on the streets.

"We have seen no sign that the Rapid Support Forces are preparing to withdraw from the streets," said Salah el-Din, the Khartoum resident.

Agence France-Presse