The South African military attacked insurgents in Cunene Province on 12 May 1980. The Angolan Ministry of Defense accused the South African government of wounding and killing civilians. Nine days later, the SADF attacked again, this time in Cuando-Cubango, and the MPLA threatened to respond militarily. The SADF launched a full-scale invasion of Angola through Cunene and Cuando-Cubango on 7 June, destroying SWAPO's operational command headquarters on 13 June, in what Prime Minister Pieter Willem Botha described as a "shock attack". The MPLA government arrested 120 Angolans who were planning to set off explosives in Luanda, on 24 June, foiling a plot purportedly orchestrated by the South African government. Three days later, the United Nations Security Council convened at the behest of Angola's ambassador to the UN, E. de Figuerido, and condemned South Africa's incursions into Angola. President Mobutu of Zaire also sided with the MPLA. The MPLA government recorded 529 instances in which they claim South African forces violated Angola's territorial sovereignty between January and June 1980.