Sudanese forces attacked a Darfur refugee camp today, leaving up to 27 dead and scores wounded, rebel leaders said.
The United Nations said it was "gravely concerned" at reports Sudanese security vehicles had surrounded South Darfur's volatile Kalma camp and that attacks had resulted in "injuries and deaths of civilians".
A spokesman for Sudan's army said officers had entered the camp to search for weapons, but insisted armed camp residents had fired on them first.
Kalma camp, long a centre of unrest, is home to 90,000 people who have fled their villages in five years of fighting in western Sudan between rebels, the government and militias.
The government has accused armed rebel supporters of taking refuge in Kalma while residents have accused government-backed militias of mounting a string of raids on the settlement.
Leaders of two Darfur rebel factions told Reuters government forces in around 100 vehicles surrounded Kalma at 5am. A UN source said there were reports shooting had started inside the camp three hours later.
"I am inside the camp Kalma. Now there is still shooting," Abakr Suleiman, a senior tribal leader inside the settlement, said at 10am."There is heavy shooting. They came into the camp and killed people. There are houses burning."
Ahmed Abdel Shafie, leader of a Sudan Liberation Army (SLA) faction, said there were 27 confirmed deaths in what he said was an attack by Sudan's army.
"The IDPs (internally displaced people) are resisting, we are expecting casualties," Shafie added. "They (the government of Sudan) want to demolish Kalma camp, they want to force people to leave."
Aid group Medecins Sans Frontieres said at least 65 people - more than half of them women and children - were treated at its Kalma clinic after being injured in the shooting.