German authorities say thieves posing as police officers have made off with 1 million euros ($1.45 million) in gold and jewelry.

The German news agency DAPD reports four thieves in a dark BMW with a police light and a red VW van with Nuremberg plates pulled the transport truck over Tuesday morning near the southern city of Ludwigsburg.

The thieves wore black pants and jackets with "police" on them and told the driver and his passenger they were customs officials confiscating the shipment.

Police say the men didn't know they were being scammed until after they were all on the highway again and the thieves stopped, tied them up and left them behind on the side of the road.

Police say they are still searching for the suspects and the vehicles.