During 1959 and 1960, violence broke out in several South African cities. In March 1960 police fired upon a crowd protesting against the pass laws in Sharpeville, killing at least 69 people and injuring many others. Demonstrations against the killings followed in many parts of the country and led to the banning of the main African opposition organisations, the African national Congress (ANC) and the Pan Africanist Congress (PAC). Both went underground, and formed armed wings, Umkhonto we Sizwe (ANC) and Poqo (PAC). By 1964 the greater part of the internal leadership of both groups had been arrested and jailed, most famously in the Rivonia arrests and trial of 1963-1964.