Ukrainian prime minister Arseniy Yatseniuk has pointed at Russia as the real culprit behind an attack on German government websites, after a group opposed to his ministry claimed responsibility for the hack.

CyberBerkut hackers had accused the prime minister of trying to claim money from the EU in order to fund the continued instability in the east of Ukraine, in an attack that preceded a meeting between Yatseniuk and German chancellor Angela Merkel.

Speaking to German broadcaster ZDF, Yatseniuk said: "I strongly recommend that the Russian secret services stop spending taxpayer money for cyber-attacks against [German parliament] the Bundestag and Chancellor Merkel’s office."

The chancellor’s spokesman Steffen Seibert yesterday confirmed that the attacks had limited access to the websites from 9am GMT yesterday, with the disruption continuing until the evening.

CyberBerkut, whose name references the riot squads that opposed the Ukrainian revolutionaries early last year, have appealed to the German people and government to stop funding and supporting the "criminal regime in [Ukrainian capital] Kiev".

Slogans on their website of "We will not forget. We will not forgive." mimicked those used by hacking collective Anonymous, an active supporter of the protestors that brought down the previous Ukrainian regime, which had close connections to the regime of Russian president Vladimir Putin.

Chris McIntosh, chief executive of communications vendor ViaSat UK, said: "The fact that Russia’s alleged cyber-attack against Germany is supposedly in response to their continued support of the Ukrainian government shows that cyber-attacks are becoming the first weapon of choice for countries in conflict."

"The lines between private, public and military targets are blurring and cyber-attacks are now being looked to as an effective way of influencing other countries’ foreign policy."