The type of devices recently planted in public places around Durban are often used in Afghanistan and Iraq, where improvised explosive devices (IEDs) account for 75% of casualties, a South African bomb expert says.
And, he adds, if the province fails to beef up its crime intelligence, more suspicious devices could be planted freely in public places.
Willem Els, an expert in crime scene handling and bomb disposal at the Institute of Security Studies (ISS), said IEDs referred to any device that could be detonated without having been made in a factory.
"You can get up in the morning and purchase common items and construct a device like the ones found. The internet could give a person, [who has] a small amount of skill, access to a lot of instructions on bomb making."
Several suspicious devices have been found around Durban over the past few days, particularly at large shopping centres. Devices were also found in a parking lot close to the Durban July at the weekend.
Els says authorities should have moved more swiftly after the first incident two months ago, when an explosive device was found at the Verulam mosque.
Following that incident, there is still "very little information", he said.
"If you had a good crime intelligence, even after the first device, there should be significant leads."
Els, who also trained bomb disposal experts and has more than two decades of experience in the field, said that while intelligence was lacking, bomb disposal units in the province were more than capable.
"They are very well equipped and well trained to follow these procedures," he says.
However, he reiterated that unless intelligence units stepped up their game, authorities would not make progress in terms of arrests.
"The problem is, even if police arrest someone, to take them to court and to get a conviction can prove challenging. Due to lack of capacity and lack of training, our investigations on these matters don't often see a high level of convictions."
Who could be planting these devices?
Els said that it was not likely that a terrorist organisation was responsible for the planting of the devices.
"They tend to take credit for bombings and planting of devices to ride the wave of the media hype and further their agenda."
He added that it could be an extortion racket.
"They could be going around to plant these bombs in your shop and threaten to detonate if you do not give them money. They are motivated primarily by greed. This is what could have happened at the Spar in Wentworth or even the Durban July."
Els said there was a third possibility - once involving a disgruntled worker
"Maybe someone is aggrieved they did not get the pay hike they wanted and [want to] get someone to do this for them or even do it themselves."
Els reiterated it was imperative that intelligence operatives narrowed in on leads.
"Without proper intelligence, police cannot move on suspects. It is like a blind man with a walking stick."
The province has battled with amateur devices planted in public areas over the past few days.
In the latest incident on Monday, police control detonated a suspicious parcel at Wentworth Spar.
On Saturday, a suspicious device was found in a Woolworths store at Gateway Mall, also in Durban, and earlier in the week, similar devices were found at the same retail chain - one in Gateway and one at The Pavilion.
The device found on Saturday, which appeared to be a cellphone attached to a pipe, did not explode.
Meanwhile, on Sunday, two explosive devices under two separate vehicles, were found in the Berea area of Durban, KwaZulu-Natal police said.
Anyone with information regarding the incidents can contact the police on 08600 10111.