Business as usual at Brussels Airport.

But just hours earlier, the airport was the scene of one of the world's biggest ever diamond heists.

Four armed and masked men in two vehicles broke through a fence surrounding the airport late Monday evening and drove up to a security van.

Within just three minutes, they made off with more than 460 million dollars worth of uncut diamonds as the gems were being loaded onto a Swiss plane.

(SOUNDBITE) (English) BRUSSELS AIRPORT SPOKESMAN, JAN VAN DER CRUYSSE, SAYING:

"We can only conclude that indeed this was a high value cargo that was stolen and therefore we can only conclude that these people were indeed very well aware of what they were doing, what they were looking for. Please understand there's an official enquiry into this matter by the police and at this moment, there is no further information I can give you on this subject."

Both vehicles sped off after the heist one of them was later found after being dumped.

No shots were fired and no one was injured in the audacious robbery.

The airport is now investigating the break in.