Police are looking for eight men who made a hole in a security fence of Brussels' international airport, drove onto the tarmac and robbed tens of millions of dollars worth of diamonds from the hold of a Swiss-bound plane.
Brussels prosecutor's spokeswoman Anja Bijnens said the armed and masked men used two vehicles in their daring Monday (Tuesday NZT) raid and within minutes made their way to the plane, took the cache of stones and drove off into the darkness.
Police found a burnt-out vehicle close to the airport later Monday night but said it was still looking for clues.
The heist was estimated at some $US50 million (NZ$60 million) in diamonds, said Caroline De Wolf of the Antwerp World diamond Centre.
"What we are talking about is obviously a gigantic sum," De Wolf told VRT network.
An airport spokesman says the robbers made a hole in the perimeter fence, and drove right up to the Swiss passenger plane that was ready to leave. The robbers got out of the car, flashed their arms and took the loot from the hold, airport spokesman Jan Van Der Crujsse said. Without firing a shot they drove off through the same hole in the fence, completing the spectacular theft within minutes, he said.
Van Der Crujsse could not explain how the area could be so vulnerable to theft. "We abide by the most stringent rules," he said.
The Swiss flight, operated by Helvetic Airways, was cancelled after the robbery. The airline declined to comment on the heist, citing the ongoing judicial investigation.
The insurance for air transport - handled sometimes by airlines themselves or external insurance companies - is usually relatively cheap because it's considered to be the safest way of transporting small high value items, logistics experts say.
Unlike a car or a truck, an airplane cannot be attacked by robbers once it's on its way, and it is considered to be very safe before the departure and after the plane's arrival because the aircraft is always within the confines of an airport - which are normally highly secured.