Robbers stole valuables worth up to $105 million from safe-deposit boxes at a Sparkasse bank branch in Gelsenkirchen, North Rhine-Westphalia, Germany, during the Christmas holiday, police announced Tuesday. The German news agency dpa reported that the heist could be one of the largest in the country's history.

The thieves gained entry to the bank by drilling through a thick concrete wall from an adjacent parking garage, police said. The incident occurred sometime during the Christmas holiday when businesses were closed. After breaching the wall, the robbers accessed an underground vault room where they proceeded to force open numerous safe-deposit boxes. The exact number of boxes affected is still under investigation.

North Rhine-Westphalia is a German state known for its museums and Gothic architecture. Its capital, Dusseldorf, features a prominent shopping boulevard and the Rheinturm telecommunications tower. The Sparkasse bank is a retail bank with numerous branches throughout Germany.

Authorities are currently investigating the methods used by the thieves and the extent of the losses. The investigation is focused on identifying any potential security vulnerabilities that may have contributed to the success of the robbery. Police are also reviewing surveillance footage from the bank and surrounding areas in an effort to identify the perpetrators.

The incident has raised concerns among bank customers regarding the security of safe-deposit boxes. Sparkasse bank officials have stated that they are cooperating fully with the police investigation and are reviewing their security protocols to prevent similar incidents in the future. The bank has also established a hotline for customers who may have been affected by the robbery. The investigation is ongoing.