BRUSSELS — In a brazen heist right out of the movies, thieves drove onto Belgium’s airport tarmac and stole more than $50 million of diamonds from a plane without firing a single shot. It took them fewer than five minutes to cut through an airport fence Monday night, drive up to a Helvetic jet in cars with flashing lights, hold up the pilot and security officials on the plane, and take 120 packages of rough and cut stones, according to the Belgium prosecutor’s office. The men carried submachine guns, were dressed in police uniforms and camouflage masks. "It was a well prepared operation. Robbers knew exactly when Brinks diamond and jewellery services truck would load” at 8:05 p.m., Ine Vanwymersch, told ABCNews.com. Vanwymersch said the thieves "forced open the fence between two construction sites,” allowing them onto the tarmac. She said the pilot and co-pilot out of the plane doing a pre-flight safety check and were held them at gunpoint along with the plane’s security detail, and it took the robbers "just three minutes” to unload the gems from the "belly” of the plane, referring to the luggage section. "It took them another two minutes to get to the tarmac and to escape in two vehicles: a black Mercedes Vito van and a black Audi A8,” Vanwymersch said. They left through the same hole in the fence, she said. None of the plane’s 20 passengers saw anything, and thieves kept details about themselves to a minimum. "We don’t know the colour of their skin or the language they spoke. We cannot comment on it,” Vanwymersch told ABC News. Agencies