Two truck drivers narrowly escaped infernos when their trucks were allegedly petrol bombed in Mpumalanga during the early hours of Tuesday morning.
The incidents took place in the small town of Bethal in Mpumalanga.
According to police, a truck driver parked next to Mica to get some rest on Monday evening and woke up to the sound of a window breaking. He then noticed that the truck was burning, police spokesperson Constable Thomas Mogadime said in a statement.
In a separate incident the same evening, another truck driver was sleeping in his truck when he woke up to see flames and bellowing smoke. He and his assistant managed to escape unharmed.
Mogadime said the estimated value of the damage was R1.75 million.
On Saturday evening, five trucks were set alight between Parys and Sasolburg in the Free State.
Police spokesperson Brigadier Motantsi Makhele said the trucks were forced to stop after a petrol bomb was thrown at one.
"It was also indicated that shots were fired [at] other trucks, forcing them to stop," Makhele said at the time.
"The drivers fled into the nearby field and four other trucks were then set alight."
When police arrived on [the] scene, firefighters had already put out the blaze and the truck drivers were treated for shock at Parys District Hospital.
On 19 November, nine trucks and trailers were torched in Heidelberg in Gauteng.
Police spokesperson Captain Mavela Masondo said preliminary investigations revealed that a white Toyota Quantum and a black VW vehicle blocked main roads on Thursday at around 20:30.
"Thereafter, a number of trucks caught fire after petrol bombs were allegedly thrown at them. Seven trucks were torched on the N3 between Heidelberg and Vosloorus while two trucks were set alight on the R103," Masondo said.
News24 previously reported that Gauteng police said they were mobilising as many resources after the incident.
"The general (acting provincial police commissioner Major General Patricia Rampota) has subsequently ordered the urgent mobilisation of maximum resources [to find] the suspects responsible for this criminal act and [bring] them to book," Masondo added.
The motive in all the incidents is unknown, according to police.