- What is the background?
It left the region awash with weapons with the multiple ethnic groups divided by bitter rivalries.
Fighting in Darfur has subsided over the years, but ethnic and tribal clashes occasionally flare, mainly over land and access to water between semi-nomadic Arab pastoralists and settled non-Arab farmers.
The transitional government, a power sharing arrangement comprised of generals and civilian figures, has pushed to build peace with rebel groups in Sudan's main conflict zones, including Darfur.
On December 31, the hybrid United Nations African Union Mission in Darfur (UNAMID) formally ended its operations in the region, 13 years after it came into being.
"The death toll from militia attacks in al-Geneina yesterday reached 48", the SUNA news agency said on Sunday, referring to the capital of West Darfur state and quoting the local branch of the country's doctors' union.
Though the levels of violence have decreased and a peace deal was agreed past year between the military and Darfuri rebel groups, raids and clashes between armed herders and farmers are still common.
The violence has reportedly pitted non-Arab and Arab tribes in El Geneina, the capital of West Darfur state.
"The armed militias spread panic in and around the city... they also carried out all kinds of human rights violations", it said in a statement.
Fighting persisted until Sunday afternoon, including in a camp hosting some of the thousands of Darfuris displaced by decades of conflict.
U.N. Secretary-General Antonio Guterres "is deeply concerned" about the violence and "calls on the Sudanese authorities to expend all efforts to de-escalate the situation and bring an end to the fighting", his spokesman, Stephane Dujarric, said.
The fighting in the state capital, El Geneina, began on Saturday after a row in which a man was stabbed to death.
Saleh said that several homes were torched in the attack, which appeared to be in revenge for Fallata tribe's killing of a Rizeigat member around a week ago.
Aid workers fear the violence could drag Darfur backwards into further conflict.
The Sudanese Professionals Association said the violence in West Darfur shows the "deficiencies" of the peace deal.
- Does it threaten the peace deal?
A conflict reportedly between ethnic Masalit people in Krinding and herders grew into a larger conflict involving armed militias.
Only two groups refrained from signing the peace deal, including one with considerable support in Darfur.
But the clashes underscore "the state of relations between communities on the opposing fronts of the unresolved civil war in Darfur", said Magdi El-Gizouli, an analyst with the Rift Valley Institute think-tank.
The violence led to local authorities imposing a round-the-clock curfew on the entire province.
Darfuris had protested the blue helmets' departure citing fears of renewed violence.