The robbery took place in the early hours of Sunday, with investigators establishing that the suspects gained access to the bank through an adjoining building.

Images released by Chile's Investigative Police showed the opening created in the concrete wall, which the suspects reportedly broke through using powerful drilling equipment.

Juan Luis Fonseca, head of the Concepcion Provincial Prefecture, explained how the criminals entered the premises.

"As the prosecutor indicated, they entered through a breach, made a breach into the interior, entered a section inside the bank and, indeed, worked with high-end, powerful tools in order to gain entry to the bank," he explained.

Police believe at least five people participated in the robbery, although investigators have not ruled out the involvement of additional suspects.

Authorities are also examining how long the operation lasted and reviewing available security recordings to establish the movements of those responsible.

"More cameras at the location are being sought. Therefore, at this moment I could not provide further details regarding what we are seeing, but there is indeed quite a lot of material inside the bank," he added.

Fonseca said the suspects may have used a vehicle during the operation.

However, investigators have faced difficulties tracing their movements because surveillance cameras outside the bank were not functioning properly.

No arrests have been reported.

Investigative Police officers are continuing forensic examinations inside the branch and gathering evidence to identify those involved in the robbery.