German banking regulator BaFin said its website has only been partially accessible since Friday after a so-called distributed denial of service attack.

BaFin took security and defensive measures after the attack which also restrict access to the website, according to a spokeswoman. All of BaFin’s other systems are working without disruption, she said.

European regulators have warned the banks they watch over that cyberattacks constitute a growing risk to their operations because they can cost money and damage perception of a firm in the eyes of its clients.

BaFin is working on restoring full access to its website, according to the spokeswoman.