The police were there not long before and they would reappear in large numbers as soon as the barrage of gunfire against the unarmed demonstrators died down and the weeping started.
But for those few minutes when lives were in the balance, the SAP disappeared. Later a Colonel Louw said it was because they had to guard white-owned property on the route of the march. But it seemed strange that the police should disappear after following the demonstrators from the beginning. Some of those who survived have little doubt that the SAP was forewarned. The police withdrew for the massacre.
It was cold-blooded murder. The marchers did indeed defy the Ciskei government's warning not to go beyond the stadium next to the roadblock and into Bisho. The ANC had said it had no intention of abiding by rules imposed by the hated 'homeland' dictatorship. But no more than a few had spilt from the stadium when the barrage started. There were a few seconds of automatic fire and then the fusillade came.
Between the road and the stadium is a large patch of open ground. People started falling. Some were obviously shot, others dropped in terror. Initially they lay flat on their faces but as machine- guns opened up from at least two directions, the demonstrators crouched low and ran. Still the bullets continued to fell them.
When the fusillade died down, the Ciskei troops finally fired their tear-gas. They had chosen to wait until afterwards, although tear-gas is obviously preferential to live ammunition if the intention is to prevent bloodshed. The marchers, some bloodied, most covered in dirt, started fires in the bush. The smoke helped dissipate the effect of tear-gas, they said.
Afterwards the area of open bush between the road and the stadium was littered with shoes, lost or thrown off in panic. Blouses hung from thorn trees, ripped from women whose lives were too threatened to worry about their dignity.
The secretary-general of the ANC, Cyril Ramaphosa, was still next to the razor-wire, lying face- down in the road. Mr Ramaphosa is rarely found angry. On this occasion he was distressed. More than once he said it was all so unbelievable.
Next to him, the ANC's head of political education, Raymond Suttner, was venting the anger. 'De Klerk unleashed his lapdog today. It's De Klerk we'll bring to account,' he said.
On the other side of the wire had cowered members of the National Peace Secretariat, mainly elderly, well-meaning white men who are supposed to prevent this kind of thing happening. The chairman, John Hall, who had just lain through some of the most terrifying moments of his life, said he would have to get the facts before he could comment.
The Rev Bob Clarke was not so cautious. 'I could feel the shots coming over the top of us. I cannot see the justification. The crowd was peaceable. It doesn't make sense,' he said.
Mr Ramaphosa went to look at the bodies being gathered in the road. He stopped by three men shrouded in blankets.
A dozen or so people knelt on the road, led by a priest in a shrill song of mourning.
The crowd drifted down the road, a few hundred yards from the border, then settled on the grass bank or just stood staring back to the top of the hill. A man in a T-shirt commemorating the Boipatong massacre in June was brushing off the dirt. Underneath the mud was recorded Nelson Mandela's words at the funerals of those victims: 'De Klerk is conducting war against the people.'
Hardly anyone noticed the black Range Rover that rolled up four hours after the killings. Behind the tinted windows could just be made out the tiny dictator, in an oversized hat, who was the trigger-man this day. Brigadier Oupa Gqozo was squeezed between two security men. He sat looking at the scene for a few minutes and left.