BERLIN — Two official German websites, including Chancellor Angela Merkel’s page, were inaccessible on Wednesday after an apparent cyberattack.
A group demanding that Germany sever ties with Ukraine and
halt financial and political support for the government in the capital, Kiev, claimed credit for shutting down the websites.




The sites were at least periodically inaccessible after about 10 a.m., according to Ms. Merkel’s spokesman, Steffen Seibert.
“Our service provider’s data center is under a severe attack that has apparently been caused by a variety of external systems,” he told reporters at a regular government news conference when asked whether Ukrainian hackers were responsible.
In a Russian-language statement posted on its website, a group identifying itself as CyberBerkut — using the slogan “We Won’t Forget. We Won’t Forgive.” – noted the support of Ms. Merkel’s government for Prime Minister Arsiny P. Yatsenyuk.
The statement said the prime minister was seeking more money from the West to prop up his country, which is faltering economically, as a way to allow what the group called Ukraine’s “criminal government” to continue to wage war against pro-Russian forces, primarily in the eastern part of the country.
CyberBerkut said it had blocked the sites of the German chancellor and the Bundestag, or lower house of Parliament.
“Berkut” in the group’s name is a reference to the special troops who supported Viktor F. Yanukovych, the former president who fled last February after weeks of antigovernment unrest.
Government officials in Berlin said in the midafternoon that they would issue statements on the situation but had no further immediate comment. Mr. Seibert and Ms. Merkel flew to London as planned.
Last March, the CyberBerkut group claimed responsibility for taking down three NATO websites in a series of distributed denial of service attacks, in which servers are flooded with traffic until they collapse.