Thieves used a large drill to break into a German bank's vault during the Christmas break and steal cash, gold and jewellery worth €30 million ($35 million), police and the bank said.
The gang smashed open more than 3,000 safe deposit boxes and made off with the loot in the raid in the western city of Gelsenkirchen.
While the criminals remained at large, hundreds of distressed bank customers gathered outside the branch on Tuesday, demanding information.
Police said the thieves drilled their way into the underground vault of the Sparkasse savings bank from a parking garage.
German businesses were closed for Christmas on Thursday and Friday last week, and investigators suspect the gang may have spent the holidays and weekend inside, breaking open the deposit boxes.
The bank said the branch was “broken into over the Christmas holidays” and that “more than 95 per cent of the 3,250 customer safe deposit boxes were broken into by unknown perpetrators”.
The raid came to light after a fire alarm was triggered in the early hours of Monday and emergency services discovered the hole.
Witnesses reported seeing several men carrying large bags in the stairwell of the parking garage during the night from Saturday to Sunday, police said.
Security camera footage showed a black Audi RS 6 leaving the parking garage early on Monday morning, with masked people inside.
'Professionally executed'
The car's licence plate had been stolen in the city of Hanover, police said.
A police spokesman told AFP that the break-in was “indeed very professionally executed”, likening it to the heist movie Ocean's Eleven.
“A great deal of prior knowledge and/or a great deal of criminal energy must have been involved to plan and carry this out,” he said.
Police said the thousands of boxes had an average insurance value of more than €10,000, and therefore estimated the total value at €30 million.
Several victims told police their losses far exceeded the insured value of their safe deposit boxes.
The police spokesman said “disgruntled customers” were outside the bank branch, which did not open for security reasons, after threats were made against employees.
“We're still on site, keeping an eye on things,” he said. “The situation has calmed down considerably,” he added.
A spokesman for the bank said it had set up a hotline for customers and that all those affected would be informed in writing as soon as possible. He said it was working with insurers to determine how to process the claims.
“We are shocked,” said press spokesman Frank Krallmann. “We are standing by our customers and hope that the perpetrators will be caught.”
