The South Sudan army says it has managed to recapture the main bastion of the country’s rebels following weeks of clashes.

Military spokesman Dickson Gatluak said Monday that government forces took control of Pagak near the Ethiopian border after forces loyal to opposition leader Riek Machar withdrew from the town a day earlier.

“This morning at 6 a.m. our forces entered the town and as we are speaking now they are in full control of Pagak,” said Gatluak, adding that the recapture of the town, located in the Upper Nile region, came almost “without a fight.”

Weeks of clashes have forced thousands to flee the Upper Nile region. Reports said the rebels had earlier resisted for days in the nearby town of Maiwut. They were pushed backed to Pagak before they decided to burn the military barracks and flee.

William Gatjiath Deng, spokesman for the opposition group SPLA-IO, said Monday that the army’s control over Pagak would not last as the opposition forces were regrouping. He said rebels were now in control of Maiwut, something the army has yet to confirm.

“So at the moment as we are speaking all our forces are surrounding Pagak right now,” Deng said, adding that rebels were preparing to take back their stronghold.

Pagak has been a key element in Machar’s insurgency since he defected as the main deputy to President Salva Kiir in December 2013 over allegations of plotting a coup.