Berlin-German investigators said Wednesday they had launched a manhunt for suspects who made off with 6.5 million euros ($7.6 million) in cash after breaking into a customs office.

“The break-in was professionally planned and carried out: three as yet unidentified perpetrators used a drill to get to the vault from an adjoining room in the cellar of the building,” police said in a statement. “From there they stole about 6.5 million euros in cash.” The heist, which struck the customs office in the western city of Duisburg, took place on Sunday November 1.  Witnesses said they had heard drilling sounds at around 6:00 am. Three hours later, three men dressed in dark clothing and dark knit caps were seen walking in and out of the building to load objects into a white van with sliding doors.

They then drove off with the van.

Another witness noticed a man walking around the customs office before getting into a car and driving off in the same direction as the van. Photographs of the man taken by the witness were published by police, who are offering a 100,000-euro reward for information leading to the arrest and/or conviction of the suspects.