In Portuguese Angola, the rebellion of the ZSN was taken up by the União das Populações de Angola (UPA), which changed its name to the National Liberation Front of Angola (FNLA) in 1962. On February 4, 1961, the People's Movement for the Liberation of Angola (MPLA) took credit for the attack on the prison of Luanda, where seven policemen were killed. On March 15, 1961, the UPA, in a tribal attack, started the massacre of white populations and black workers born in other regions of Angola. This region would be retaken by large military operations that, however, would not stop the spread of the guerrilla actions to other regions of Angola, such as Cabinda, the east, the southeast and the central plateaus.