Two of those arrested are women, one aged 36 and the other in her 20s, according to a police press release. A 36 year old man has also been arrested.
It is not yet clear whether the people being held were actually present at the robbery itself, or if they played another role.
The robbery, which took place early in the morning, was violent. Two people wearing masks and dark clothes and armed with automatic weapons blew open the security vehicle at the scene and made off with a large sum of money. Precisely how much cash the robbers got away with has never been revealed.
The two female guards who were driving were forced out and injured by the explosion, which ripped a hole in the side of the vehicle.
As well as the two armed robbers, police are working on the assumption that there was a third person driving the waiting escape car. That was found soon afterwards in a commuters’ car park as the robbers continued in another vehicle.
Police have also found a car which was used before the robbery and which, like the first escape car, was stolen in Finspång.
All three people who are now in custody were arrested on Tuesday in a joint operation by Västra Götaland police, the National Police Department and the Stockholm force.
The robbery had a direct, although short-term, effect on Swedes’ daily lives. The transport union’s regional safety controller in Stockholm, Gothenburg and Malmö stopped all cash transits in the cities on the day of the raid, leading to shortages in ATM machines and stockpiles of cash in stores.
But the vehicles were back on the road a few days later after the Swedish Work Environment Authority decided to tighten the regulations concerning cash deliveries and collections.
The amount being transported was reduced, and security firms were told to vary their routines more frequently.