Sudanese government forces have captured a rebel stronghold in the restive border state of Blue Nile.

Sudanese officials say the army has succeeded in pushing the rebels out of Kurmuk, a town located close to South Sudan, which broke away from Sudan in July. Officials said the town has been “totally liberated and secured” from forces loyal to the southern neighbor.

Yasir Arman, whose party has ties to South Sudan's ruling party, confirmed Kurmuk's takeover Friday. In an interview with VOA , he said there is a “massive displacement” of civilians from the area, and he accused Sudan of committing atrocities.

Arman said Sudan's army seized the city with the help of “janjaweed” militia brought in from the Darfur region, and the South Sudan militia of George Athor that has fought the South Sudan government.

There was no word on casualties.

Fighting in Blue Nile broke out a little more than two months ago. Sudanese forces are also fighting rebels in the state of Southern Kordofan and clashed with southern forces earlier this year in the oil-rich Abyei region.

In another development Friday, the U.N. Security Council called on the Sudanese army and South Sudan's forces to immediately withdraw from the disputed Abyei region.

The council said it deplored the failure of both governments to pull back their forces.

Sudan recognized South Sudan when the new nation declared independence in July, but the countries have yet to settle disputes over borders and oil revenue. South Sudan took most of the oil-producing areas in the split but cannot export the oil without Sudan's Red Sea facilities.

Blue Nile and Southern Kordofan were battlegrounds during Sudan's 21-year north-south civil war. During the war, fighters in both states sided with the south.