Investigators estimate that burglars stole about €30 million during a break-in at a bank in the western city of Gelsenkirchen, police said on Tuesday.

A police spokesperson described the break-in as highly professional, saying it required extensive planning, inside knowledge, and significant criminal resolve to carry out.

What do we know about the Gelsenkirchen robbery?

Police said the perpetrators gained access to the bank from a parking garage, drilling a large hole into the vault room and later escaping through the same route with the stolen items.

More than 3,000 safe-deposit boxes in the vault were forced open, containing cash, jewelry, and gold. Based on an average insured value of about €10,000 per box, police said initial rough estimates put the total losses at around €30 million.

The burglary came to light on Monday after a fire alarm was triggered and alerted emergency services. Police said the perpetrators gained access to the bank from a parking garage, drilling a large hole into the vault room and later escaping through the same route with the stolen items.

Witnesses told police they saw several men carrying large bags in the parking garage stairwell during the night into Sunday. Investigators have already reviewed initial surveillance footage, which reportedly shows a black Audi RS 6 leaving the garage early Monday morning with masked occupants inside. The vehicle's license plate had previously been stolen in the northern German city of Hanover, police said.

Who were the victims?

Customers gathered outside the Sparkasse branch on Monday and again on Tuesday seeking information. The nearby city of Cologne's Kölner Stadt-Anzeiger newspaper reported that many of those affected were customers of Turkish heritage who had stored gold or gold jewelry in their safe-deposit boxes. Some victims told police their losses far exceeded the insured value of their boxes.

Police have asked affected customers to contact the bank directly rather than filing individual criminal complaints. The Sparkasse bank is collecting personal details and damage reports and forwarding them to investigators on a daily basis, they said.

Edited by: Saim Dušan Inayatullah