While Russia was wielding its veto at the United Nations, and Ukraine reported an attempt by Russian forces to enter Ukrainian territory adjacent to Crimea, 50,000 people have marched in Moscow to demand their government leave Ukraine alone.

Carrying banners proclaiming "the occupation of Crimea is Russia's disgrace" the marchers are protesting against Russia's incursion into the peninsula, some even comparing the occupation with Germany's invasion of the Sudetenland – controversial in a country which lost over 20 million people during the second world war.

The protesters included Maria Alyokhina and Nadezhda Tolokonnikova, former members of the punk band Pussy Riot, who were imprisoned after performing in a Moscow cathedral in 2012. After the march demonstrators congregated at Prospekt Sakharova where activist Ilya Yashin addressed the crowd condemning the Russian government.

Pro-Russian demonstrators march through Moscow Reuters

"We are patriots and Putin is Russia's enemy," he said. "Ukraine is a brotherly nation and we will not allow them to march us into a fratricidal war."

However, elsewhere in Moscow an estimated 15,000 demonstrators marched in support of the Russian policy in Ukraine, and pro-Russian marches also took place in the Russian-majority regions to the east of Ukraine itself. Three people have been killed in fighting, including two shot dead in a gun battle in Kharkiv.

Acting president of Ukraine Oleksander Turchinov condemned the pro-Russian demonstrators in the east of the country: "You know as well as we do who is organising mass protests in eastern Ukraine - it is Kremlin agents who are organising and funding them, who are causing people to be murdered."

However, Russia insists the culprits in the Kharkiv shootings were linked to a far-right group called the Right Sector, whose offices were being stormed by pro-Russians. Several nationalists were reported to be arrested.

Crimeans will vote tomorrow on whether to leave Ukraine and join the Russian Federation. The majority of Crimeans are of Russian descent but many Ukrainians are afraid of what the future may hold if the peninsula comes under Russian rule.

Western leaders have condemned the referendum, with US Secretary of State John Kerry saying a vote in favour of Russian ties amounts to "a backdoor annexation of Crimea".

The Russian Federation has just vetoed a US-backed resolution to declare Sunday's referendum illegal. In all, 13 countries voted in favour of adopting the resolution and even Russia's traditional allies China abstained, demonstrating the extent of the unease in the international community about Russia's actions in Ukraine.

As tensions continue to rise, Ukraine's interior ministry has released a statement that reveals Ukrainian forces have repelled an attempt by Russian forces to enter a region adjacent next to Crimea: "Units of Ukraine's armed forces today...repelled an attempt by servicemen of the armed forces of the Russian Federation to enter the territory of Kherson region on Arbatskaya Strelka. This was repelled immediately."