(CNN) -- Some 10,000 demonstrators against the Ukraine's decision to not sign a landmark trade deal with the European Union descended on a square outside a monastery early Saturday in response to a police crackdown on the earlier protests. The emboldened demonstrators waved Ukrainian and EU flags and sang the national anthem outside the St. Michael's Golden-Domed Monastery, where groups of protesters retreated earlier after a sweep by riot police left seven people hospitalized and dozens under arrest at Independence Square. Three top opposition leaders called for resignation of President Viktor Yanukovych as well as new presidential and parliamentary elections, according to a statement released by Vitaliy Klitchko, Arseniy Yatsenyuk and Oleg Tyagnybok.
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New: 10,000 demonstrators gather after violent police crackdown; opposition leaders call for president's resignation
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Riot police detain dozens of protesters in Kiev's main square -- state media
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United States condemns "violence against protesters" in Independence Square
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Interior Ministry says riot police responded to "provocations by protesters" -- state media
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