Berlin's Governing Mayor Kai Wegner and Senator for the Interior and Sport Iris Spranger said in a joint statement on Friday that the city would not give in to the attackers' demands.

"The state of Berlin will not be blackmailed," they said.

The Berlin State Criminal Police Office, the public prosecutor's office and federal security authorities are working closely to investigate the suspected perpetrators of the cyberattack on the Berlin state network, the statement said.

"The investigations are being conducted with the utmost urgency," it added, while authorities are also working to determine the nature and extent of the compromised data.

The authorities did not disclose the amount of ransom demanded by the attackers.

Ongoing forensic investigations following the cyber incident have also uncovered further data exfiltration from the Berlin state network of the Senate Department for Mobility, Transport, Climate Protection and the Environment, according to the statement published on the Mayor's official website.

The content and extent of the affected data are still being assessed.

"It cannot be ruled out that personal or other non-public data may also be affected," the statement said.

The data exfiltration occurred between August 7 and 12, before network shutdowns were imposed at the Senate Department for Mobility, Transport, Climate Protection and the Environment and the Senate Department for Urban Development, Construction and Housing on August 14.

The cyberattack forced several online systems to be taken offline, according to media reports.

The Rhysida ransomware group, which is believed to operate from Russia and Eastern Europe, has claimed responsibility for the attack, the BBC reported. The group was also linked to a cyberattack on the British Museum in 2023.