Bunagana, a town in the east of the democratic Republic of Congo, has been captured from M23 rebels by the army.
"Bunagana is completely under our control. We had been fighting since the early morning," DR Congo's government spokesman Lambert Mende told the AFP news agency.
The town near the Ugandan border was the main base of the group and their political leader Bertrand Bisimwa was reported to have surrendered to Ugandan officials after crossing the border.
However M23 officials denied that Bisimwa had fled.