German government websites, including Chancellor Angela Merkel's page, were hacked on Wednesday in a cyber attack claimed by a group demanding that Berlin sever official ties with the Ukrainian government.
The attack, against which counter-measures were taken, had left the sites periodically inaccessible since 10 a.m. (0900 GMT), her spokesman Steffen Seibert said.
“Our service provider's data center is under a severe attack that has apparently been caused by a variety of external systems,” he told a news conference when asked if Ukrainian hackers were responsible.
In a statement on its website, a group calling itself CyberBerkut took responsibility.
"Berkut" is a reference to the riot squads used by the government of Ukraine's former pro-Russian President Viktor Yanukovich, who was ousted during violent protests last February.
“CyberBerkut has blocked German Chancellor and the Bundestag's (lower parliamentary house) websites,” it said on its website.
The claim could not be independently verified.
“We appeal [to] all people and [the] government of Germany to stop financial and political support of criminal regime in Kyiv, which unleashed a bloody civil war,” it said.
Ukrainian Prime Minister Arseny Yatseniuk was to meet with German President Joachim Gauck in Berlin later Wednesday.