( CNN ) -- Ukrainians angry at their government 's last-minute decision to suspend talks with the EU clashed for a second day with police in the capital Kiev on Monday . A day earlier , tens of thousands of protesters tried to break through a cordon around government buildings . On both occasions , police responded with batons and tear gas to disperse them . At the heart of the protests is Ukraine 's about-turn after a year of insisting that it was intent on signing a historic political and trade agreement with the European Union , . On Thursday , however , the government decided to suspend talks with the EU . Ukraine 's president , Viktor Yanukovych , is in a tight spot . Under severe economic pressure from Ukraine 's giant neighbor , Russia , not to join the EU , he also was facing a key EU demand that he was unwilling to meet : free former Prime Minister Yulia Tymoshenko , his bitter political opponent . Two years ago , she was found guilty of abuse of office in a Russian gas deal and sentenced to seven years in prison in a case widely seen as politically motivated . Her supporters say she needs to travel abroad for medical treatment . `` Yanukovych has decided it 's more important to keep Tymoshenko in prison than to integrate Ukraine closer toward Europe , '' said David Kramer of Freedom House , a U.S.-based nongovernmental organization . `` He has left his country vulnerable to Vladimir Putin 's threats and pressure . That will be Yanukovych 's legacy if he does n't reverse course . '' The deal , the EU 's `` Eastern Partnership , '' was aimed at creating closer political and economic ties and fostering economic growth among the nations of Eastern Europe and the Caucasus , including Ukraine , Moldova , Georgia , Armenia , Azerbaijan and Belarus . The agreement was expected to be signed this week at a summit in in Vilnius , Lithuania . CNN 's Jill Dougherty contributed to this report .
Police respond with batons and tear gas . Ukraine 's president , Viktor Yanukovych , is in a tight spot . He has been accused of corruption by the opposition ( who are demanding his resignation ) but he also needs to keep Russia from invading eastern Ukraine. The EU wants him to release his bitter political opponent .