Thieves used a large drill to break into a safe at a high street bank branch in western Germany and steal an estimated €30m (£26m; $35m) in cash and valuables, police have said.

A police spokesman likened the break-in to the Hollywood heist film Ocean's Eleven, telling AFP news agency it was 'very professionally executed'.

During the heist at Sparkasse savings bank in the city of Gelsenkirchen, thieves broke open more than 3,000 safe deposit boxes containing money, gold and jewellery. Gelsenkirchen Police said they became aware of the crime after a fire alarm was set off in the early hours of Monday morning.

Currently, no arrests have been made and the perpetrators remain at large. Police said the thieves had used the 'quiet Christmas days' to rob the building on Nienhofstrasse in the Buer district.

Initial investigations suggest they gained access to the bank, and escaped, via an adjacent parking garage. Witnesses have reported seeing several men carrying large bags in the staircase of the garage overnight on Saturday into Sunday.

Police said video footage shows a black Audi RS 6 leaving the garage, on De-La-Chevallerie-Strasse, early on Monday morning.

The hole into the underground vault room was discovered when a fire alarm went off, prompting police and fire brigade searches.

Affected bank customers have been asked to contact Sparkasse bank, which has set up a hotline. The bank's entrance was secured following a large crowd of customers seeking information after the break-in. Sparkasse informed customers that 95% of the safe deposit boxes had been forcibly opened, suggesting a high likelihood of impact on customer accounts.

The bank emphasized that the contents of safe deposit boxes are insured up to €10,300 and advised customers to check for additional home insurance coverage.