SUDANESE rebels say they've attacked five areas in North and South Kordofan states, widening an anti-government offensive in one of their most audacious acts in years.

"This is a significant shift in the war in Sudan," Abdel Wahid Mohammed al-Nur, who heads a faction of Darfur's Sudan Liberation Army, warned on Saturday.

"We are heading to Khartoum," he said.

"This is not a joke."

Residents of Umm Rawaba, the second-largest town in North Kordofan, said rebels arrived on Saturday morning on at least 20 vehicles for a brief occupation.

They fired their weapons into the air, causing panic but met no initial resistance from security forces, townspeople said.

"We just saw some drones in the air," one resident said, adding that the insurgents looted the market.

Other residents said the town's inhabitants cowered in their homes as rebels shot at government buildings and policemen before withdrawing.

North Kordofan has been largely free from the rebel activity taking place in the Darfur region to its west, and South Kordofan to its south.

"This is part of our strategy to overthrow the regime," said Gibril Adam Bilal, spokesman for Darfur's Justice and Equality Movement (JEM) which is part of a rebel coalition.

"This is an attack deep in Sudanese territory."

JEM and factions of the Sudan Liberation Army from Darfur are grouped in the Sudan Revolutionary Front (SRF) with insurgents from South Kordofan and Blue Nile states.

Sudan Armed Forces (SAF) spokesman Sawarmi Khaled Saad said troops confronted the rebels after they reached Abu Kershola in the far north of South Kordofan.

But rebels then looted Kareem Allaha village before targeting Umm Rawaba town in North Kordofan, Saad said.

The spokesman for the Sudan People's Liberation Movement-North (SPLM-N), which is based in South Kordofan and Blue Nile states, said the rebel coalition "captured" five areas.

Nur, the other rebel, also said five communities had been attacked.

Originally published as Sudan rebels widen offensive