Strange because Umm Ruwaba is further east than El Obeid and En Nahud… how on earth did they get past those places?  And why not attack El Obeid itself?

Fighters with the Justice and Equality Movement, or JEM, attacked the town of Umm Ruwaba in North Kordofan State, which lies between Darfur to the west and Khartoum to the northeast, on Saturday. The assault is a rare venture outside Darfur and South Kordofan State for the rebels.

via Rebels From Darfur Attack in North Kordofan State – NYTimes.com.