Around 300 anti-war protesters took to the streets of Moscow in the last few hours.
They were protesting Russia's build up of forces in the Crimea.
The action has lead to a full military mobilisation by Ukraine, with acting President Olexander Turchynov ordering the closure of airspace to all non-civilian aircraft. US President Barack Obama described Russia's troop deployments as a "violation of Ukrainian sovereignty".
People held posters saying "No to war", while some also held Ukrainian flags and ribbons in the national colors of yellow and light blue.
OvdInfo, a rights group that tracks arrests at demonstrations, said that 285 protesters were arrested.
This protester was arrested as he held up a blank piece of paper.
While anti-war protesters were arrested, Russian authorities have agreed to allow a rally Sunday afternoon in support of Putin's policies of intervention in Ukraine.
An invitation to the rally posted on the pro-Kremlin United Russia party page said that many in Ukraine were, "faced with persecution and violence because they speak Russian and are friendly toward Russia."
Alan White is a news editor for BuzzFeed News and is based in London.
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