Location: Kiev, Большая Житомирская street.Reports of up to 18 people died in Ukraine's capital in the worst day of violence since anti-government demonstrations erupted 12 weeks ago.Kiev plunged into chaos when protesters attempted to push towards the parliament and president Viktor Yanukovych's party headquarters. Protesters armed with rocks and petrol bombs fought running battles with riot police, who replied with water canons, stun grenades and rubber bullets.Opposition leader Arseniy Yatsenyuk told the protesters police were using real bullets. "We see that this regime again has begun shooting people; they want to sink Ukraine in blood. We will not give in to a single provocation," Yatsenyuk said.Up to seven policemen have died, some by gunshot. . As the riots continue into the night, the death toll is expected to rise, as more reports come in from Kiev.