Security Police Chief, Brigadier C.F. Zietsman, announced that about 4,000 South African exiles were undergoing guerrilla training in Mozambique, Angola, Tanzania and Libya; about seventy-five per cent of them were training with Umkhonto We Sizwe (MK), the military wing of the African National Congress (ANC).
References

SAHO uMkhonto We Sizwe [online] Available at: www.sahistory.org.za [Accessed on 3 June 2013]|

ANC Manifesto of Umkhonto we Sizwe Leaflet issued by the Command of Umkhonto we Sizwe, 16th December 1961[online] Available at: www.anc.org.za [Accessed on 3 June 2013]