Sudan rebels attack city, push closer to capital KHARTOUM (Reuters) - Rebels from Sudan's Darfur region attacked a city in a neighboring state on Saturday, taking their fight closer to the capital Khartoum, witnesses said. The attack marks the biggest push of a rebel alliance that seeks to topple President Omar Hassan al-Bashir. Fighting had hitherto been limited mainly to the remote regions of Darfur and South Kordofan and Blue Nile states, which border South Sudan. The Justice and Equality Movement (JEM) - which launched an unprecedented assault on Khartoum in 2008 - said insurgents stormed the city of Um Rawaba in North Kordofan state, around 500 km (300 miles) south of the capital. JEM did not say whether it would try to advance further. Sudan's army told state media it was still fighting rebels inside Um Rawaba, the state's second largest city. It accused the insurgents of destroying a power plant, petrol stations and a telecommunications tower. "Battles are still ongoing," army spokesman al-Sawarmi Khalid told state news agency SUNA. Armed men in 20 trucks drove into Um Rawaba, an important market for a Sudanese agricultural export product, gum arabic, and looted a market and several commercial banks, residents told Reuters. A JEM spokesman denied any pillaging by rebels. "Our forces are controlling parts of eastern North Kordofan and Um Rawaba," spokesman Gibril Adam said. The goal of this attack is to weaken the government to realize our strategic plan to topple the regime. The government later reopened the road between Khartoum and the North Kordofan state capital El-Obeid, which had been blocked by fighting, state governor Mutassim Mirghani Zaki Uddi told the state-affiliated Sudanese Media Center (SMC). "The rebels have fled southwards," he said. They were unable to stay in Um Rawaba. Events outside Khartoum are difficult to verify in the vast African country. Um Rawaba is a two-hour drive from Kosti, Sudan's biggest Nile river port. JEM forces drove across hundreds of miles of desert to attack the Khartoum suburb of Omdurman in May 2008 and were stopped just short of the presidential palace and army headquarters. The group was one of two main rebel forces that took up arms against Sudan's government in 2003, demanding better representation for Darfur and accusing Khartoum of neglecting its development. Khartoum mobilized militias to crush the uprising, unleashing a campaign that Washington and activists described as genocide. Sudan's government denies the charge and accuses the Western media of exaggerating the conflict. In 2011, JEM teamed up with two other Darfuri groups and the Sudan People's Liberation Movement-North (SPLM-North) which took up arms in South Kordofan and Blue Nile states around the time of South Sudan's secession. They formed the "Sudanese Revolutionary Front," which says it fights to topple Bashir to secure a fairer share of government in a country dominated by three Arab tribes. Fighters of the SPLM-North sided with southern Sudan during decades of civil war that ended with a peace deal in 2005, which paved the way for South Sudan's formal breakaway in July 2011. Sudan on Wednesday started peace talks with the SPLM-North after a thaw in relations with South Sudan. Khartoum has accused Juba of backing the rebels but made no fresh accusations the two agreed to resume crucial cross-border oil flows last month. Additional reporting and writing by Ulf Laessing; Editing by Mark Heinrich