As a western German city slumbers over Christmas, thieves break into bank vaults and disappear with millions of people.

Robbers broke into the vault of a savings bank in western Germany over Christmas and stole cash, gold and jewelry worth an estimated $105 million, police and banks said.

The perpetrators used a large drill to drill through a thick concrete wall at a savings bank branch in Gelsenkirchen, North Rhine-Westphalia, police said on Tuesday. The thieves broke in from an adjacent parking lot, entered underground vault rooms and forced open more than 3,000 safes.

Police spokesman Thomas Nowaczyk said investigators believe the total value of the stolen items may be between 10 and 90 million euros ($11.7 million to $105.7 million).

German news agency dpa reported that the robbery could be one of the largest in the country’s history.

Sparkasse confirmed the branch was “broken into over the Christmas holidays” and said “more than 95 per cent of 3,250 customer safes were broken into by unknown offenders”.

The crime is believed to have occurred while businesses were closed during the extended Christmas holiday. Police suspect the gang may have been in the building for several days, using the long holiday weekend to break into safes without being detected.

The theft didn’t come to light until the early hours of Monday morning, when the fire alarm was triggered. Emergency crews arriving on the scene discovered the hole leading to the vault.

Witnesses later told police they saw several men carrying large bags through the parking lot stairwell between Saturday and Sunday.

Surveillance video also showed a black Audi RS 6 leaving the garage early Monday morning with a masked person inside. The vehicle’s license plate was later identified as belonging to a car stolen in Hannover, more than 200 kilometers (124 miles) northeast of Gelsenkirchen.

Ocean’s Eleven style

A police spokesman described the operation as highly organized and compared it to Hollywood-style robberies akin to “Ocean’s Eleven.”

He told AFP the break-in was “really very professional”.

“The planning and execution of this operation must have involved a substantial amount of prior knowledge and/or a substantial amount of criminal energy,” he added.

Police said the average insured value per safe was more than 10,000 euros ($11,700). However, officials said some victims reported that the contents of their boxes were worth far more than the insured amount.

Hundreds of customers gathered outside the bank on Tuesday, demanding answers. The branch remains closed for security reasons after staff were reportedly threatened.

“I couldn’t sleep last night. We didn’t get any information,” one man told WBC, adding that he had used the safe for 25 years and kept his retirement savings there.

Police spokesman Novachik said officers were still on scene monitoring the situation. “We are still on the scene and closely monitoring the situation,” he said, adding that “the situation has calmed down significantly”.

The bank said it has set up a hotline for affected customers and will contact them in writing as soon as possible. It added that it was working with insurance companies to determine how compensation claims would be handled.

“We are shocked,” said bank spokesman Frank Krallmann. “We stand with our customers and hope the perpetrators are caught.”

Police said the suspect remains at large and the investigation is ongoing.

A spokesman for Gelsenkirchen Savings Bank did not immediately respond to a request for comment.