Thieves drill into German bank vault and steal millions

Thieves have stolen tens of millions of euros worth of property from safety deposit boxes inside a German bank vault that they drilled into during the holiday lull.

Some 2700 bank customers were affected by the theft on Monday in Gelsenkirchen, police and the Sparkasse bank said.

About 3000 safety deposit boxes, which made up more than 95 per cent of the bank's inventory, were broken into.

Investigators believed the theft was worth between 10 million euros and 90 million euros ($A18 million-$A158 million), police spokesman Thomas Nowaczyk said.

German news agency DPA reported that the theft could be one of Germany's largest.

The bank remained closed on Tuesday, when some 200 people showed up demanding to get inside.

Each safety deposit box is insured for 10,300 euros unless a bank customer additionally insures it privately, Sparkasse said on its website.

A fire alarm summoned police officers and firefighters to the bank branch shortly before 4am on Monday.

They found a hole in the wall and the vault ransacked.

Police believe a large drill was used to break through the vault's basement wall.

Witnesses told investigators they saw several men carrying large bags in a nearby parking garage at the weekend.

Video from the garage showed masked people inside a stolen vehicle early on Monday, police said.

The fire alarm was also triggered on Saturday but authorities did not find any damage.