I can't think of an armed struggle in which innocents were not killed to some degree. That's why pacifists object to armed struggle under all circumstances.
I happen to think that the armed struggle in South Africa was just and correct despite the errors and indeed the crimes that were committed in its name.
Current President Thabo Mbeki was leader of the ANC's military arm, Umkhonto we Sizwe. According to wikipedia:
Units of ANC exiles had MK camps in the "frontline" states neighboring South Africa, most prominently Angola where MK was allied to the MPLA government, and fought alongside Angolan and Cuban troops at the critical engagement in Cuito Cuanavale. MK troops were also allied with ZAPU (rival to Robert Mugabe's ZANU) in then-Rhodesia, with FRELIMO in Mozambique, and with SWAPO in Namibia.
Landmark events in MK's military activity inside South Africa consisted of actions designed to intimidate the ruling power. In 1983, the Church Street bomb was detonated in Pretoria near the SA Air Force Headquarters, resulting in 19 fatalities and 217 persons injured, some of whom were military, and many were civilians. During the next 10 years, a series of bombings occurred in South Africa, conducted mainly by the military wing of the African National Congress.
In the Amanzimtoti bomb on the Natal South Coast in 1985, five people were killed and 40 were injured. A bomb was detonated in a bar on the Durban beach-front in 1986, killing three persons and injuring 69. In 1987, an explosion outside a Johannesburg court killed three people and injured 10; a court in Newcastle had been attacked in a similar way the previous year, injuring 24. In 1987, a bomb exploded at a military command centre in Johannesburg, killing one person and injuring 68 military or civilian personnel.
The bombing campaign continued with attacks on a series of soft targets, including a bank in Roodepoort in 1988, which four were killed and 18 injured. Also in 1988, in a bomb detonation outside a magistrate’s court killed three. At the Ellis Park rugby stadium in Johannesburg, a car bomb, killed two and injured 37. A multitude of bombs in “Wimpy Bar” fast food outlets and supermarkets occurred during the late 1980s, killing and wounding many people. In most of these events the victims were civilians, and of all races. Several other bombings occurred, with smaller numbers of casualties. Along with these mainly urban bombings, there was a campaign, from 1985 to 1987, in the rural areas of the Northern and Eastern Transvaal, aimed at the farming and rural communities. There were about 23 deaths.<3>.
http://en.wikipedia.org/wiki/Umkhonto_we_SizweThis is the armed struggle that Nelson Mandela refused to condemn and upheld during his entire 27 years in prison. Even when released, he did not condemn it, nor did he ever condemn "necklacing," or other methods of killing suspected informers and spies.