The United States said Thursday it will only be ready to mediate a truce between Sudan's warring parties when they get "serious", after the army left negotiations and the latest ceasefire unraveled.
The army on Wednesday blasted bases of the Rapid Support Forces (RSF) after pulling out of the truce talks in the Saudi city of Jeddah, accusing its rival of breaching the ceasefire meant to bring in aid.
The United States said there had been "serious violations of the ceasefire by both sides".
"Once the forces make clear by their actions that they are serious about complying with the ceasefire, the United States and the Kingdom of Saudi Arabia are prepared to resume facilitation of the suspended discussions to find a negotiated solution to this conflict," a State Department spokesperson said.
"These violations have led us as a facilitator of these talks to seriously question whether the parties are ready to take the actions needed to meet the obligations they have undertaken on behalf of the Sudanese people," he said.
In both north and south Khartoum on Wednesday, troops loyal to army chief Abdel Fattah al-Burhan attacked key bases of the RSF led by commander Mohamed Hamdan Daglo, residents told AFP.
One witness said there was "heavy artillery fire from army camps" in the capital's north, on the 47th day of a war that researchers said has claimed 1,800 lives.
Another reported "artillery blasts on the RSF camp in Al-Salha" in southern Khartoum -- the largest paramilitary base and arsenal in the city.
The attacks came two days after Saudi and US mediators said the warring parties had agreed to extend by five days the initial week-long humanitarian truce.