Activists chanting "Russia!" broke through police lines Sunday and stormed several government buildings in eastern Ukrainian regions seeking independence from Kiev following last month's fall of a Kremlin regime.

Clashes in Donetsk and similar rallies in the heavily Russified cities such of Lugansk and Kharkiv provided another reminder to the untested pro-Western leaders in Kiev of the monumental task facing them after their February 22 overthrow of president Viktor Yanukovych.

Russia needs to understand it is not in its interest "to have a collapsing state in its neighborhood", German Foreign Minister Frank-Walter Steinmeier said at the close of two-day talks with his 27 European Union counterparts.

As the Ukraine-Russia dispute over gas prices intensified, Germany's Steinmeier stressed that Europe needed Russia to help rescue the new authorities in economically distressed Kiev.

Russia's top intelligence agency admitted Saturday that a high-ranking officer was in Kiev during February bloodshed, but said he was there to ensure "security" of the Russian embassy.

"We confirm that (FSB general) Sergei Beseda was in Kiev on February 20-21... to determine the level of security necessary for the Russian embassy in Ukraine and other Russian facilities in Kiev," Russian agencies quoted a source in the powerful Federal Security Service (FSB) agency as saying.

Russian lawmakers on Friday gave initial approval to a bill forbidding "rehabilitation of Nazism" that will punish historians denying Nazi crimes during World War II but could also be used against the opposition.

The bill introduces a new criminal charge for "denying facts" established by the Nuremberg tribunal regarding the crimes of the Axis powers, as well as "disseminating false information about Soviet actions" during the war.

Europe must stand united as Russia challenges the continent's resolve over the Ukrainian crisis unfolding on its eastern borders, Lithuania's top diplomat told Agence France Presse on Friday.

"Russia is challenging our unity, our way to handle the crisis," Foreign Minister Linas Linkevicius said in an interview on the sidelines of a meeting with his European Union counterparts.

A Russian court on Friday decided to partially grant the appeal in case of Pussy Riot punks, ruling that their 2012 cathedral stunt was not directed against a "social group" and shaving one month off their sentence.

The three women, Maria Alyokhina, Yekaterina Samutsevich, and Nadezhda Tolokonnikova, were convicted in 2012 after staging a protest performance in a cathedral during Vladimir Putin's presidential campaign.

Russia on Friday launched a criminal investigation into breaches of hygiene at a cheese factory after footage of bare-chested workers bathing in vats of milk went viral on the Internet.

The Investigative Committee announced it was probing the factory in the Siberian city of Omsk for producing food that could cause harm to health after photographs of grinning workers bathing in foaming milk horrified Russians.

A senior U.S. official voiced confidence Thursday that the global response to Russia's annexation of Crimea would have a "chilling effect" that deters China from contemplating similar action.

Since Russia seized Crimea last month, U.S. lawmakers and Asian diplomats have asked about the message sent to an increasingly confident China -- especially with regard to Taiwan, which is claimed by Beijing and relies on U.S. support.

NATO hit back on Thursday at accusations by Moscow that the Western alliance was in violation of international law and accused Russia of fomenting "propaganda and disinformation" over the crisis in Ukraine.

"No, of course we haven't violated the Rome Declaration and I'm actually surprised that Russia can claim that NATO has violated its commitments because Russia is violating every principle and international commitment it has made," NATO Secretary General Anders Fogh Rasmussen said.

Russian Foreign Minister Sergei Lavrov on Thursday said there was a large amount of evidence to contradict claims by Kiev that Ukraine's former authorities used snipers to kill scores in February.

The version of events announced by Kiev Thursday "contradicts huge amounts of evidence that proves the contrary," Lavrov said, mentioning a leaked telephone call in which the European Union's foreign affairs chief Catherine Ashton discussed the possible involvement of the Ukrainian opposition in the shootings.