Transport Minister Blade Nzimande is demanding answers after a fatal train crash in Pretoria north left at least three people dead and hundreds injured.
More than 600 commuters were injured when two trains collided near Pretoria's Mountain View train station on Tuesday.
Nzimande said that Passenger Rail Agency of South Africa (Prasa) management should account for the incident.
Reports suggest that the two trains were both travelling on the same line towards Pretoria from Mabopane when they collided.
The minister said preliminary investigations had revealed that cable theft was to blame for the accident. He wants a full brief on the role of security companies who were meant to be guarding the railways.
"These companies take hundreds of millions of rands, but we do not see any difference.
"I have said to the chairperson of the board that I want answers within the next few days as to what action is taken to address the security issue," said Nzimande.
He said that no security company should be awarded a tender by Prasa "if it is not able to demonstrate what it has done in order to deal with issues of theft, and failure to force such demonstrations would be turning Prasa into an ATM".
The minister endured the rain at the crash scene as he examined the wreckage first-hand and was briefed by engineers on site about what had led to the trains colliding.
"We need a strategy, but at the same time we need accountability from management, because families may have lost breadwinners from this fatal crash."
Nzimande has called on the Railway Safety Regulator of South Africa (RSR) to go "deeper in its investigations". He also challenged his department to look into rail safety in the country.
In October, the Gauteng High Court in Pretoria issued a supervisory order instructing Prasa to comply with the safety requirements set out by the RSR.
Subsequently, the regulatory body made known its intention to revoke Prasa's safety permit after two trains collided on October 4 near Van Riebeeck station in Kempton Park during manual authorisation.
Prasa took to the courts in an effort to keep operating, despite safety concerns, and the RSR eventually rescinded its decision to suspend, seemingly so that millions of commuters across the country would not be inconvenienced.
However, the United National Transport Union (Untu) has not spared Nzimande from blame, saying both the minister and Prasa must be held accountable.
Untu's general secretary Steve Harris said that the collision could have been prevented if Prasa had ensured that its management had implemented the terms of the court order that had been granted against it by Judge Cassim Sadiwalle in October.
"In terms of the court order, Prasa had to ensure that a supervisor oversees each and every manual authorisation of a train control officer to eliminate human errors from occurring, as was the case with all the train collisions in Gauteng over the last three years," said Harris.
Nzimande has now instructed Prasa to ensure that its automated signalling system is fully installed urgently, while it also considers ways to ensure that cables, among other equipment, are secured.
Prasa board chairperson Khanyisile Kweyama said that some stations were closed off during the December holidays, with officials installing the automated signalling system, and assured that 90% of the project had already been completed.
"If we can fix all these other side issues (theft), we should be able to properly roll out the authorisation system," Kweyama said.
She said that the board had also committed to the rail regulator that the system would be implemented soon.