Clashes between Sudanese forces and rebels in conflict-hit Darfur have forced some 10,000 people to flee their homes, the UN-African Union mission in the region (UNAMID) said on Monday.
The fighting flared last week around Jebel Marra, a mountainous area straddling South, Central and North Darfur states seen as a stronghold of the rebel Sudan Liberation Army led by Abdelwahid Nur (SLA-AW).
"Some 8,403 affected civilians, mostly women and children, have taken refuge" in the vicinity of a UNAMID base near the town of Sortoni in North Darfur state, UNAMID said in a statement.
"According to the Office for the Coordination of Humanitarian Affairs (OCHA), 2,385 people have also been displaced to Tawila, North Darfur," it said.
The peacekeeping mission, which deployed to Darfur in 2007, said it was trying to verify reports of "people trapped in areas where combat is ongoing".
Ethnic insurgents have been battling President Omar al-Bashir's forces in the western Darfur region since 2003, when they rebelled against his Arab-dominated regime, complaining they were being marginalised.
The counter-insurgency Bashir unleashed on Darfur, combining ground forces, aerial bombardments and allied militia, saw him accused by the International Criminal Court of alleged war crimes, crimes against humanity and genocide.
Bashir announced a ceasefire last year in Darfur and South Kordofan and Blue Nile states, which he extended for one month during a speech on December 31.
Although Jebel Marra was the scene of intense fighting earlier last year, Darfur had been relatively calm until last week.
UNAMID said peacekeepers at its base in the town of Nertiti in Central Darfur state reported "sporadic heavy artillery gunfire and bombings in the Jebel Marra area" on Saturday.
Sudan's military has said it is committed to the ceasefire but also that it responds to attacks on its positions.
The SLA-AW has accused the government of sending militiamen to attack the area, saying they have beaten back several waves of assaults.
It has not been possible to independently verify reports from the region, as media access to Darfur is strictly limited by the Khartoum government.
The latest fighting comes as representatives of other major Darfur-based rebel groups met Sudanese officials in Ethiopia for "unofficial" talks.
The UN children's agency UNICEF last week voiced its concern about the surge in fighting in Sudan's conflict-battered peripheries.
"Children unfortunately continue to bear the biggest burden of one of the most protracted man-made disasters, in some areas for over a decade," the statement said.
Some 300,000 people have been killed in the conflict in Darfur since 2003, according to the UN, and ethnic conflicts and rising criminality have further deepened instability in parts of the region.
There are also more than 2.5 million people displaced by unrest living in the Darfur region, the UN said.