A year after the United Democratic Front (UDF) was formed, Security Police raided their offices. This came amid nationwide unrest which started on 3 September 1984 in Sebokeng, Vaal. The UDF was an umbrella organisation of anti-apartheid groups. It filled a void created when organisations such as the African National Congress (ANC), Pan Africanist Congress (PAC), South African Communist Party (SACP) and others were banned under the Unlawful Organisations Act. The UDF was launched at Mitchell's Plain in Cape Town. 
References

O’Malley P. ‘1984’, from Nelson Mandela Center of Memory and Dialog, [online], available at www.nelsonmandela.org.za (Accessed: 02 October 2012)|

South African History Online, ‘The people armed, 1984-1990’, [online], available at www.sahistory.org.za (Accessed: 02 October 2012)