Eight men drove on to a runway and robbed millions of pounds of diamonds from an aircraft.
In scenes reminiscent of a Hollywood crime caper, the raiders crashed through a perimeter fence in two cars and drove at high speed on to the runway at Brussels airport where a jet bound for Switzerland was being loaded with the precious gems.
The robbers seized the stones from a Brinks transport truck and fled into the darkness through the same hole in the fence, said local reports. Hours later, police found a burnt-out van near the scene.
How much was stolen was unclear. but early estimates suggest between $50m and $130m (£32m-£84m). The raid took no longer than a few minutes, Brussels police said.
No shots were fired and nobody was injured, it was reported. It is understood that the diamonds were rough cuts.
The robbery was labelled one of the biggest ever by Antwerp World Diamond Centre spokeswoman Caroline De Wolf.
"What we are talking about is obviously a gigantic sum," she told Belgium's VRT broadcaster