Thieves used a helicopter and explosives early Wednesday to rob a cash depot in Stockholm, police and witnesses said, in what appeared to be a well-planned and expertly executed heist.
Two or three men lowered themselves from the helicopter onto the roof of the building used by security services company G4S around 5 a.m.
Minutes later several explosions were heard and witnesses saw what appeared to be money bags hoisted into the helicopter that left the scene.
There was no immediate estimate of how much money the robbers got away with.
Police helicopters at the Stockholm police helicopter base were unable to take up pursuit since a suspected bomb was placed outside the hangar entrance, police said.
Sharp spikes were also spread near the depot, preventing police vehicles from approaching it.
A major police operation has been launched in the search for the robbers.
The operator of an aviation school near Norrtalje, 70 km north of Stockholm, later reported that a Bell 206 Jet Ranger helicopter had been stolen from a hangar.