Eleven civilians also died, including three who were shot. A police spokeswoman said 159 police were wounded, including 39 who were shot.
The coordinator for the opposition's medical response team, Oleh Musiy, said more than 400 protesters were injured.
He also claimed that about 20 had died, but this could not independently be confirmed.
One of the civilians was found dead after protesters stormed the office of the president's Party of Regions.
Police pushed them away, but when firefighters arrived to put out a fire, they discovered the body of an office employee, Kiev's emergency services said.
Justice Minister Olena Lukash, a close Yanukovych aide, accused the opposition of violating earlier agreements with the government and blamed protest leaders for the violence.
In Washington, Vice President Joe Biden expressed his ‘‘grave concern'' in telephone call to Yanukovych, urging him to pull back government forces and exercise maximum restraint.
The White House said Biden also called on Ukraine's government to address the protesters' ‘‘legitimate grievances'' and put forward proposals for political reform.
Earlier, U.S. Secretary of State John Kerry urged both sides to end the violence, halt their ultimatums and hold high-level talks.
U.S. Ambassador Geoffrey R. Payatt also threatened both sides with sanctions. ‘‘We believe Ukraine's crisis can still be solved via dialogue, but those on both sides who fuel violence will open themselves to sanctions,'' Payatt said on Twitter.
