Three taximen, including a taxi owner, were killed on Wednesday night in two separate incidents in Kagiso on the West Rand.
The three all belonged to the Greater Kagiso Taxi Association (GKTA).
This brings to seven the number of members of the same association who have lost their lives to taxi ambushes since last year.
The GKTA's deputy chairman, Thomas Dinkwetse, was shot with an AK-47 assault rifle eight times in the head in July last year.
In another incident, a Mpumalanga taxi owner who went missing last week was found dead and buried inside his house on Saturday morning.
The body of 41-year-old Richard Mkhabela, of Komatipoort, was exhumed by police after one of his workers noticed blood inside the room.
"After exhuming him we found that his assailant had used an axe to kill him - the axe was left stuck in his forehead," Tonga police spokesman Constable Mzwandile Nyambi said yesterday.
Dinkwetse had been trying to weed out crooked members of the association since last year.
Three months after Dinkwetse's death the general secretary of the association, 51-year-old David Mokgosi, was also gunned down.
He was shot dead by a group of gunmen outside his Kagiso home.
An AK-47 assault rifle was also used. And like Dinkwetse, Mokgosi foretold his death.
In the latest incident, a taxi owner, Sipho Mosai, and Mafafoke Aloycius Mathitsa, 44, were shot at about 9pm.
Jonathan Mpuru, 46, was shot and killed at approximately the same time as Mosai and Mathitsa. He had been in the industry for about five years.
His body was found at Nancefield hostel in Soweto with bullet wounds in the head.
His employer, who did not want to be named, said he became worried when the driver did not return his vehicle at about 8pm.
"I tried calling him on his phone but it was on voicemail. I called the tracking company to try and trace where my car was but they could not detect it."
Soweto police spokesman Inspector Kay Makhubela confirmed that Mpuru's body was found at the hostel.
"He was shot at close range. A case of murder is under investigation," Mpuru said.