Doctors have said that at least 18 people have been killed in fighting in the western Sudanese conflict region of Darfur.
In addition, 54 others were injured, the West Darfur State Doctors' Committee announced on Monday evening.
The violence began on Saturday in El Geneina, sometimes written as al-Junaynah, the capital of West Darfur state.
"The conflict appeared [to be] between tribal components in the state and that the attack was still continuing with heavy weapons right now, and a state of emergency and a curfew would be declared in the city of El Geneina," Governor Muhammad Abdullah al-Duma told dpa.
The same city had last seen a similar outbreak of violence in January, when a member of the Masalit people killed a member of an Arab community.
The militias had used the incident as an excuse to attack the town.
The Darfur region has been troubled for years.
Fighting broke out there in 2003 between population groups demanding more political participation and the government of the then president Omar al-Bashir.
Government forces and the allied Arab militia Janjaweed brutally attacked the population, killing an estimated 300,000 people.