By Michael Morrah
The improvised explosive device, or IED, that killed three New Zealand soldiers overnight contained more than 20 kilograms of explosives.
A former New Zealand commander who's worked in Bamiyan says the bombmakers are constantly coming up with more sophisticated techniques to injure and kill.
IEDs are the biggest killers in both Afghanistan and Iraq. In Afghanistan alone, more than 16,000 have been cleared or detonated in the past year.
"The ways that they are detonated can be numerous," says Richard Hall, former New Zealand Defence Force commander. "It could be a pressure plate, it could be a time device or it could be some form of remote device using radio, microwave, radar or whatever to set off the explosive."
Most modern military vehicles, including the kiwi Humvees, have technology to block remote signals to IEDS. But Mr Hall says the devices and detonators are always being modified.
"There is a constant battle of technology that is going on. The insurgents are watching our drills, our procedures, in the same way we are watching theirs."
IEDS can be made out of anything from fertiliser to plastic explosives, or more commonly in Afghanistan, abandoned ammunition, and can be planted in the ground or detonated from moving vehicles.
Security expert Darren Morton of Patronus International says they're a weapon of choice for insurgents.
"Because they are low cost, they're extremely easy to manufacture into an explosive device... they have maximum devastation at the scene, so could quite easily take out a military tank."
"This was a very large bomb," says Prime Minister John Key. "I mean, over 20 kilos of explosives as we understand it, so it's a very significant bomb."
The remnants of that bomb and any other IEDS found in the aftermath of the massive blast are now being examined.
3 News