Six Romanians have been arrested on allegations they stole mobile phones and laptops from the back of a tractor-trailer as they followed it down a German autobahn at 60 miles per hour, Dortmund police said Tuesday.

"It was an extremely dangerous stunt — like an action film," said Manfred Radecke, a spokesman for Dortmund police.

Officers, having been tipped off about the gang's tactics, were able to stake out an area and watch the thieves in action last week, Radecke said.

In the nighttime darkness, with their lights off, the men drove up behind a transport truck.Once in place, one man climbed onto the hood of his own car, then used a bolt cutter to break a lock on the trailer door before heaving it open and climbing inside. He then handed boxes of electronics back to a second man on the car hood, who loaded them into the thieves' vehicle, Radecke said.

A second car blocked the left lane during the operation to prevent other cars from pulling too close, he said.Because both cars had their headlights off, Radecke said, the truck driver never noticed he was being robbed.Police received a tip about the thieves after a driver reported witnessing a similar stunt two weeks ago.

Radecke said that five of the "autobahn pirates," as the Berliner Zeitung newspaper dubbed them Tuesday, appear to have traveled from Romania for the operation and that one lives in Dortmund.

"They won't tell us where they trained, how often they did this," Radecke said. "If any other German police departments have seen odd truck thefts, we hope they contact us."