Riot police and demonstrators clashed in Kiev after a rally in which opposition leaders called for President Viktor Yanukovic and his government to resign.
The protesters had swept through the streets of the capital in a sea of blue and gold the colours of both the EU and Ukraine before arriving at Independence Square.
The events which sparked the riot police to fire tear gas and use stun grenades are disputed. Opposition leaders said they wanted a peaceful protest and that the violence was stage managed, “provocation” to justify a security clampdown.
Authorities said 53 people had to be treated on the scene and 14 of them were taken to hospital.
Russian media sources say some of the protesters have been detained while its reported by police 100 officers were injured.
Reports suggested President Viktor Yanukovich who was holding meetings with officials in the suburbs of Kiev is poised to introduce a state-of-emergency on Monday.
Euronews correspondent Angelina Karyakina on the streets of Kiev said, “The Ukrainians were not given any explanation for the brutal crack-down of the peaceful rally last Friday. Now the protests are becoming more radical.
‘Some tried to storm the government buildings and demand the resignation of the government and the president. That’s exactly what the goals of the opposition are, but they want to achieve it in a peaceful way, and have called on supporters to continue their rally in Independence square.”