The Portuguese Army steadily pushed the UPA back across the border into Congo-Kinshasa in a brutal counteroffensive that also displaced some 150,000 Bakongo refugees, taking control of Pedra Verde, the UPA's last base in northern Angola, on 20 September 1961. Within the next few weeks Portuguese military forces pushed the MPLA out of Luanda northeast into the Dembos region, where the MPLA established the "1st Military Region". For the moment, the Angolan insurgency had been defeated, but new guerrilla attacks would later break out in other regions of Angola such as Cabinda province, the central plateaus, and eastern and southeastern Angola.