Clashes in Sudan's Darfur region have resumed with at least 21 people reported dead just one month after intense inter-tribal fighting left hundreds dead and forced the biggest displacement of people in the area in recent years.
In January, fighting between two Arab tribes, the Beni Hussein and the Rizeigat, over the control of a gold mine left more than 100 people dead and displaced around 130,000 people.
The latest clashes on Thursday in El Sireaf, an area in the north, "lasted for eight hours after some Rizeigat troops attacked the area," according to a Bani Hussein leader who asked not to be identified.
At least 21 people were killed and 33 wounded in the fighting, accroding to the leader, who described the situation as "very bad".
The UN Office for the Coordination of Humanitarian Affairs (OCHA) supplied emergency food to El Sireaf and most other affected areas, but in a report said that security remains a "major concern".
"The number of displaced people in different locations is constantly changing as people continue moving around," the OCHA said.
In South Darfur, rebels of a Sudan Liberation Army (SLA) faction led by Minni Minnawi said they had attacked an army post near Nyala, the region's largest city.
"Government forces fled into the city centre so we managed to seize weapons they left behind," SLA official Nur el-Daim Ahmed said.
Army spokesman al-Sawarmi Khalid could not be reached for comment. A resident confirmed fighting in the area.
"The rebels arrived with four cars and attacked the army in an area around 15km from Nyala where the government presence is weak," said the resident, declining to be named.
Fighting between the army and another SLA faction in the central Jebel Marra area in January displaced 30,000 people.
Events in Darfur are hard to verify as Sudan restricts travel by journalists, aid workers and diplomats.
The UN says at least 300,000 people have been killed and more than one million people displaced since civil war erupted in the region in 2003. The government puts the death toll at 10,000 people.