Vitali Klitschko, the UDAR (Punch) party head, helps anti-government protesters carry a wounded man. (Yury Kirnichny / AFP Getty Images)

As protests turned deadly violent Tuesday in Kiev, two of the Ukraine’s more vocal and visible leaders are men who became household names in the world of sports.

Vitali Klitschko, the former boxing champion and the head of the pro-Western Udar opposition party in Ukraine, urged protesters to continue their actions while Sergei Bubka, the former pole-vaulting great, urged peace from the Winter Olympics in Sochi. Klitschko addressed a crowd of about 20,000 Wednesday, telling people to defend their camp even as fires burned around it.

“We will not go anywhere from here,” Klitschko told the crowd (via the Associated Press) at the main encampment at Independence Square. “This is an island of freedom and we will defend it.”

From the Winter Olympics in Sochi, Bubka, who heads Ukraine’s Olympic Committee, begged citizens to end the violence that has the country, he said, on “the brink of catastrophe.”

Violence erupted erupted after weeks of calm, with at least 25 people killed and 240 injured in the latest protests over President Viktor Yanukovych’s rejection of a trade deal with Europe and subsequent decision to turn to Russia for financial help. As police moved toward the camp, it became clear, The Washington Post’s Will Englund writes, that “Ukraine is heading for an even deeper divide. The hostility that the opposition feels toward Yanukovych is intense and widespread, especially in the western part of the country. Having turned to Russia for much-needed financial help, Yanukovych may finally have burned his bridges to the West with Tuesday’s developments, leaving him in danger of being a weakened and unpopular supplicant to Moscow.”

Klitschko has made no secret of his desire to be president, retiring from boxing last December to focus on a run for the presidency in 2015, and expressed frustration after a late Tuesday meeting with Yanukovych.

“I am very unhappy because there was no discussion,” Klitschko said. “They don’t want to listen.”

Earlier this month, Klitschko’s brother Wladimir, also a boxing champion, spoke to raise awareness for what’s happening in Ukraine at the Super Bowl and admitted that he is “worried for the safety of everybody, including my brother.”

“I just want to spread the word and say what is going on in the Ukraine and point out that we do have an issue that unfortunately could become a civil war, and much more people could die,” Wladimir Klitschko told the Associated Press. “And we could lose another country, the Ukraine, to dictatorship.”

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