What damage can four kilos of explosives do?

In Dagsådalen outside Östersund, the field hunter group exercises regularly. We had to follow up with some professional officers when they had an internal training where about 14 kilos of explosives, distributed on three different charges, would be detonated.

"We are going to blow ice that will make it impossible to cross the watercourse," says Mikael Jonsson, who is a specialist officer in the Field Hunter Group.

During the exercise, the charges were placed under the ice in the water on a pond.

- It's about 40 centimeters of core, says Mikael Jonsson.

During the exercise itself, the entire area was canceled and once the actual detonation happened no one could be closer than 400 meters.

- It is the safety distance in this case but sometimes we have up to a kilometer. Safety is A and O. We have clear regulations and work a lot with risk assessments that point to, among other things, the safety distances that apply to different types of detonations, says Mikael Jonsson.

Thus, in the apartment in Torvalla 4.2 kilos of explosives and just over 30 explosive capsules were found.

- I do not want to comment on the specific case but in general, four kilos can cause great damage, says Mikael Jonsson.

Explosives have different effects depending on whether it is detonated indoors or outdoors.

- If it is outdoors and exposed it does less damage than if you enclose it in something like in a house or in a car or something.

It depends on the pressure wave formed.

- When something is detonated it becomes a gas flow that goes much faster than the sound and hence it becomes a pressure increase, says Mikael Jonsson and continues:

- And if we have stuff around this course then it will move. Ceilings and walls can give way, it can be glass panes that break or metal pieces that fly away, he says.

Something that, in turn, can hurt and at worst kill people nearby.