More than 500 fighters from the Sudan Liberation Army launched a surprise attack on Sheiria in South Darfur on Monday, military sources say.
The UN mission in Sudan has urged restraint on all sides, after an increase in fighting following last week’s resumption of peace talks.
Over two million people have been made homeless by two years of violence.
Both the rebels and pro-government militia have launched attacks in the last few days, with casualties reported on all sides.