JOHANNESBURG -  Nineteen of the 20 Boeremag accused have so far been convicted of high treason resulting from a far-rightwing conspiracy to overthrow the government.

Judgment against the last accused will be concluded on Monday.

Judge Eben Jordaan found the five; Herman van Rooyen, Rudi Gouws and brothers Johan, Kobus and Wilhelm Pretorius guilty of negligently causing the death of Claudia Mokone in Soweto in October 2002.

Mokone died when the group detonated a bomb on a railway line in Soweto and a piece of steel landed on her shack.

Judge Jordaan said although no houses were visible from the railway line and the bomb was detonated at midnight, anyone planting a bomb had foreseen that someone could die.

He accepted evidence that the five had decided on the spur of the moment to murder Mandela when they saw in a newspaper he would open a school in  Bolobedu near Tzaneen.

The attempt was described in detail in Wilhelm Pretorius’s war diary, in which he referred to Mandela as ‘‘that k....r’’ and said his death would be the sign they had been waiting for (to initiate a war against the government).

Three of them had travelled to Tzaneen with a home made bomb with the plan to detonate the bomb at the school.

The bomb was instead put in a ditch next to the road they hoped Mandela would use.

They had even prayed the weather would not allow Mandela to travel by helicopter.

The plan was to detonate the bomb when Mandela arrived with fishing line strung across the road.

When they heard the sound of a helicopter, they realised Mandela ‘‘can be allowed to go on breathing’’.

The bomb was dismantled after Van Rooyen and Wilhelm Pretorius, who were dressed in army uniforms, convinced a passing policeman they were busy with ‘‘an exercise’’ and the bomb was ‘‘part of their equipment’’.