Sabotage in South Africa; Guerrilla raids aim at gaining 'legitimacy'

Attacks by guerrilla insurgents are on the rise in South Africa. And while government security efforts are growing in step, the attacks are largely succeeding in earning publicity and a sense of legitimacy for the black nationalists reponsible, analysts here say.

In recent months bombs have exploded with surprising regularity at obviously carefully selected locations in South Africa. Clearly the incidence of sabotage has been on the rise this year, informed sources say.

The most recent blast pitched nine suburbs of Pretoria temporarily into darkness Dec. 14 after five limpet mines severely damaged a municipal power station. The blast was nearly identical to one a month earlier at a different power station near Pretoria, also using Soviet-made limpet mines.

The banned African National Congress (ANC) claimed responsibility for the most recent bombing and for a number of bombings elsewhere in South Africa this year. The ANC is the most popular political movement among South Africa's urban blacks, according to a recent poll by a Johannesburg newspaper.

The basic ANC military strategy, these analysts say, is to attack ''hard targets'' and for the most part avoid civilian casualties. For purposes of gaining legitimacy internationally and domestically as a ''liberation force'' rather than a ''terrorist group,'' the ANC ''is careful to create the impression they are fighting by established rules'' by steering clear of civilian targets, says security specialist Dr. M. Hough of the Institute for Strategic Studies at the University of Pretoria.

Basically, ''the strategy is working,'' says John Barratt of the South African Institute of International Affairs.

An interesting development is the apparent expansion of ANC activity into rural areas through the black ''homelands.'' Police stations in both Bophuthatswana and Venda were attacked in recent months, withufquoteThe basic ANC military strategy is to attack 'hard targets' and for the most part avoid civilian casualties

the ANC reportedly taking credit.

Like many ''armed struggle'' movements, ''the ANC believes its eventual victory will come from rural areas,'' Dr. Hough says. He believes the terrain of South Africa makes this strategy highly problematic, but he says the ANC pattern this year seems to clearly indicate an expansion beyond urban targets.

The homelands offer several advantages. Without the elaborate influx control laws of South Africa, they are easier for banned black organizations to operate in. Fragmented borders make control of who comes and goes in the homelands difficult. And the South African police cannot operate as freely in the homelands, although one homeland leader recently complained about South Africa's disregard for its borders on security patrols.

The homelands also stand out among blacks as shining examples of South Africa's ''apartheid,'' or separation of the races, policy. ''They are natural targets,'' says Mr. Barratt.

Still, analysts believe the publicity advantage of urban targets makes them the preferred sites for terrorist bombings.

Overall the targets appear to be selected either for their impact on large numbers of people - like power stations - or their symbolic value. On Dec. 9 well-coordinated bombings took place 900 miles apart - at a government office in Cape Town and a court house in Soweto.

The South African government strategy is to release only sketchy information about terrorist bombings, apparently in the hopes of keeping publicity to a minimum. Meanwhile the government is tightening security protection at so-called key points under legislation passed last year. It is also aggressively trying to identify and lock up ANC members.

After last year's major acts of sabotage against South Africa's Sasol synthetic fuels plants, security at the facilities has been increased to a level twice what was orginally envisioned for the facilities.

Analysts say the ANC's mode of operation is basically unchanged. Operating primarily from bases in Mozambique, its members filter into South Africa through Swaziland. Although the ANC receives Soviet support, it denies being a puppet of the communists.