Rebels attacked a city in central Sudan on Saturday, looting a market and several banks, witnesses said.
The Justice and Equality Movement - insurgents from Sudan's western Darfur region who say they are fighting for fairer government across the whole country - said they attacked Um Rawaba in neighbouring North Kordofan state.
"Our forces are controlling parts of eastern North Kordofan and Um Rawaba," JEM spokesman Gibril Adam told Reuters.
The group, which has clashed with the government before outside Darfur and attacked Khartoum in 2008, did not say why it had launched the assault.
Armed men in around 20 trucks drive into Um Rawaba, the state's second largest city around 500km (300 miles) south of the capital Khartoum, and opened fire, several residents said.
The men looted a market and several commercial banks, witnesses added.
Sudanese officials could not be immediately reached for comment.