Koetle, 45, is one of three people applying for amnesty for the Fox Street court bombing on May 20, 1987, which killed four policemen.
Koetle told the amnesty hearing in Johannesburg he made sure only policemen were on the scene when he detonated the bomb, using a remote control device.
"We solely targeted policemen. I was to make sure that only policemen would be on the scene."
Koetle said the order for the bombing was given by SA National Defence Force chief General Siphiwe Nyanda, who was MK commander of Transvaal at the time.
The car bomb exploded minutes after a decoy limpet mine detonated nearby.
"The bomb was to explode after the limpet mine when police would have already cordoned off the area.
"This was discussed by me and General Nyanda," Koetle said.
Nyanda's legal representative AP Landman, who is also representing the other applicants, said he was appearing for the SANDF chief as an implicated person and not as an applicant.
Landman said Nyanda, one of 37 ANC members who had received blanket amnesty, was not contesting the evidence which implicated him in the car bomb.
The blanket amnesty had however been set aside and Nyanda's amnesty application would be dealt with at a later stage, together with the applications of other ANC members, Landman said.
Koetle said he detonated the 100kg car bomb shortly after the limpet mine exploded in a flower pot.
He said the decoy bomb was used to get as many policemen and as few civilians on the scene. Koetle said it was known police practise to cordon off a bombed area.
Koetle said used the remote control device to detonate the bomb when he saw policemen on the scene.
Constables Weyers Botha, Kobus Wilkens, Andre Duvenhage and Christoffel Botha were killed. Three other policemen and 11 civilians were injured.
Asked by the legal representative for the victims' families, Jan Wagener, what he would have done if emergency personnel arrived on the scene, Koetle said it would have been very unfortunate.
"A mission is a mission and I had an objective to complete."
"Was the objective to kill as many policemen as possible?" Wagener asked.
"Yes," Koetle replied.
He said no distinction was made between white or black policemen.
"What we were fighting was injustice. Anybody seen to enforce this injustice was the enemy."
Koetle said he was not proud of what had happened. "One can never be proud of war. I was merely sending a message."
Wagener's clients are provisionally opposing the applications.
Applicant William Mabele, now a sergeant in the SANDF, was 19 years old when he drove the car bomb to the court with Koetle.
Mabele said he supported what had been done because he too had been a victim of police brutality.
Another MK commander who has applied for amnesty for the court bombing, Solly Shoke, now a bridadier in the SANDF, earlier on Wednesday also testified that the court bombing had been Nyanda's idea.
Asked by Wagener why he and Nyanda did not have the guts to attack people who could defend themselves, and rather targeted defenceless people, Shoke said: "The police were part and parcel of the government machinery."
Shoke said it was unfortunate that the previous government had allowed the political situation to deteriorate to the extent that it did.
The hearing was postponed to Friday, when further evidence on the court bombing and the 1988 Ellis Park bombing will be heard.
The application of Dick Hlongwane for landmine attacks between 1978 and 1980 and another application by Shoke for the bombing of several police stations will also be heard.