Russian investigators on Friday launched a probe into three associates of top opposition leader Alexei Navalny for alleged fraud during his Moscow mayoral campaign.

The Russian Investigative Committee said in a statement that the probe targets three Navalny associates -- Moscow city councillor Konstantin Yankauskas, and businessmen Nikolai Lyaskin and Vladimir Ashurkov -- accused of embezzling funds gathered for his campaign.

Russia lodged a furious protest with Britain on Thursday after Prince Charles reportedly compared President Vladimir Putin to Adolf Hitler, with Moscow saying the comments were unworthy of a king-in-waiting.

The Russian deputy ambassador to London went to the Foreign Office for urgent talks following the reported remarks by the heir to the throne during a trip to Canada.

Russia's defense ministry said Thursday that four trains and more than a dozen planes had taken equipment and troops away from regions bordering Ukraine.

After President Vladimir Putin ordered the troops to return to bases, four trains loaded with arms and 15 Ilyushin-76 transport planes carrying troops departed from bases in the Rostov, Belgorod and Bryansk regions on Wednesday, the ministry said in a statement.

Australia Wednesday announced further sanctions against allies of Russian President Vladimir Putin as it reaffirmed its "clear and unequivocal support for the territorial integrity and sovereignty of Ukraine".

The financial sanctions and travel bans were expanded to cover an additional 38 unnamed Russians and Ukrainians and 11 entities. A total of 50 people are now affected.

Britain's Prince Charles stoked controversy during a visit to Canada by comparing the recent actions of Russian President Vladimir Putin's to those of Adolf Hitler, the Daily Mail reported Wednesday. 

The British newspaper said several witnesses heard the prince make the comment to Marienne Ferguson, a 78-year-old who fled the Nazis aged 13 and lost family members in the Holocaust.

Held up by many as the best hope for Ukraine, Sunday's presidential vote will make little difference to the one man the West blames most for the country's crisis -- Vladimir Putin.

Bent on countering Western ambitions in Ukraine, Russia's leader will never accept a vote that cements the authority of Kiev's new government, analysts say.

Russia said Monday it had ordered troops near the border with Ukraine to return to their bases, just days ahead of a presidential vote aimed at bringing the country out of deep crisis.

The move could ease tensions, but both Washington and NATO -- which noted it was the third time Moscow had made such a claim -- said they saw no sign of a withdrawal.

Russian President Vladimir Putin heads to China on Tuesday to shore up eastern ties as relations with the West plunge to new lows over the Ukraine crisis.

During a two-day visit to Shanghai, Putin and Chinese host Xi Jinping will seek to clinch a raft of agreements including a landmark gas deal crucial for Moscow as Europe seeks to cut reliance on Russian oil and gas.

President Vladimir Putin said Thursday that Russia is "still open" to talks on Ukraine's gas debt, accusing the EU of failing to make specific proposals to help prevent a cutoff of supplies from next month.

In an open letter to European leaders, Putin also called on Brussels to "more actively engage" in finding ways to stabilize crisis-hit Ukraine's economy.

Russian President Vladimir Putin will next week travel to China for a visit expected to see Moscow and Beijing seal a landmark gas agreement, the Kremlin said on Tuesday.

During the May 20 visit to Shanghai, Putin will oversee the signing of a number of "important agreements" in trade and energy, the Kremlin said without providing further details.