The capture in North Kordofan severs Rapid Support Forces supply lines and opens a road toward West Kordofan, officials say.
The Kordofan region, situated between Darfur and central Sudan, has become one of the deadliest fronts in the country's ongoing civil war.
Sudan's army chief says he rejects any settlement to end the war, despite US pressure to agree to a humanitarian truce.
Military vows continued operations against the paramilitary Rapid Support Forces after reporting territorial gains in the region.