At least 18 civilians were killed in a market in Khartoum on Thursday, after the military announced withdrawing from truce talks the day before.
Military shelling and aerial bombardments hit the capital's market, injuring over 100. The French AFP news agency cited a neighborhood group which organizes aid as saying the situation was "catastrophic."
The number of casualties was even higher than the initial tally, a member of a local neighborhood committee told the Reuters news agency. They said several people were either treated at the scene or buried at home by relatives who feared the perilous trip to hospital.
The Sudanese military, led by Abdel-Fattah Burhan, has been using its air force to attack members of its rival paramilitary Rapid Support Forces (RSF) since the fighting started on April 15. The latter have nestled in the capital's neighborhoods, and the confrontation has left many Khartoum residents trapped in their homes to avoid the fighting.
Clashes continued elsewhere in the capital and its surroundings, with residents of northern Omdurman and southern Bahri reporting heavy artillery fire.
"We are being terrorized by the sounds of heavy artillery around us. The house has been shaking," 49-year-old Nadir Ahmed in Omdurman told Reuters. "Where is this ceasefire we hear about?"
Sudan's army suspended talks with the RSF on Wednesday, accusing the paramilitary group of failing to implement "any of the terms of the agreement" and continuously violating the ceasefire.
The truce talks were ongoing in Jeddah throughout most of May, mediated by Saudi Arabia and the US. They produced a fragile week-long cease-fire that was extended by five more days this week, despite multiple violations.
The US acknowledged on Thursday "serious violations of the ceasefire by both sides." A State Department spokesperson warned that Washington would only mediate if the warring parties were "serious."
"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," the AFP news agency quoted the spokesperson as saying.