KIEV, Ukraine — Tens of thousands of Ukrainians flooded central Kiev late Friday to mark one year since the bloodiest day of last year's Euromaidan revolution that ousted the country's pro-Russian president, Viktor Yanukovych, and installed a pro-Western government, setting in motion the events that have led to a deadly and ongoing war.

Some 49 people died and around 100 more suffered gunshot wounds from police snipers on Feb. 20, 2014, in the worst day of violence against the hundreds of thousands of protesters who hunkered down on Kiev's Independence Square for three months in the freezing cold. Around 100 people died during clashes with riot police around the square between Feb. 18 and 20 last year. They have been dubbed the "Heavenly Hundred."

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Crowds dressed in patriotic blue and yellow paid an emotional tribute to them on Friday, reciting prayers and singing songs as the protesters' electrified images flashed on big screens over the square. They chanted, "Heroes do not die!"

The next morning in central Moscow, thousands of Russians responded, marching under the slogan "We won't forget! We won't forgive!" to mark a year since the overthrow of Yanukovych. The Kremlin deems Ukraine's revolution a "coup." Organizers said more than 20,000 people participated in the "Anti-Maidan" march. Russian state media reported as many as 35,000 took to the streets.