ITV News Europe Editor James Mates reports from Ukraine:
Ukraine opposition leader Vitali Klitschko has spoken of anti-government protesters anger that he has shaken the hand of President Yanukovich.
But he told ITV News, he had to do that and sign the peace deal to "stop the fighting".
ITV News' Europe Editor James Mates is in Kiev:
Opposition leader and former heavyweight boxer Vitali Klitschko says Ukraine's President Viktor Yanukovych is responsible for the violent unrest that has engulfed the country's capital Kiev.
Speaking to ITV News Europe Correspondent Emma Murphy in Kiev, Mr Klitschko said he was "very worried" for the future of his country.
Asked who he blamed for the conflict, he replied: "The man who has absolute power in our country - President Viktor Yanukovych".
Vitali Klitschko, the leader of the Ukranian opposition party, believes overnight action against anti-government protesters by police in Kiev to remove barricades and tents from a camp has closed the path to any kind of compromise.
Boxing champion Vitaly Klitschko told the crowd of anti-government demonstrators in Kiev that their protests must remain peaceful.
"We do not want to be kept quiet by a policeman's truncheon," he said.
Mr Klitschko, the leader of the opposition Udar (Punch) party, is increasingly seen as a national leader-in-waiting.
Addressing the anti-government protests in Ukraine's capital of Kiev, he demanded the release of political prisoners, the resignation of the government and early elections.
"This is a decisive moment when all Ukrainians have gathered here because they don't want to live in a country where corruption rules and where there is no justice," the leader of the opposition Udar (Punch) party said.
Heavyweight boxing champion and opposition party leader Vitali Klitschko met demonstrators in Kiev and urged them not to give up control of Independence Square in the capital.
Thousands of protesters are reportedly still in the capital waiting for new demonstrations against President Viktor Yanukovych over the government's decision to suspend preparations to sign a landmark trade pact with the EU.
Talks between the government and opposition will reportedly be held later today.
World boxing champion Vitali Klitschko has formally announced that he will run in the Ukrainian presidential election in 2015, the Moscow Times reports.
"To put an end to all speculation and attempts to dispose of me as a possible candidate I want to announce that I am running for president," Klitschko is cited as saying in parliament.
The 42-year-old heavyweight boxer founded the opposition Udar party in 2010 and has campaigned to bring "European standards of life" to the former Soviet country.
His bid for the presidency could be thwarted by a new bill ruling out candidates that have not lived in Ukraine for the last 10 years.
A Ukrainian boxer Vitali Klitschko known as "Dr. Ironfist" has announced he plans to run for the country's presidency in 2015, the state-run Ukrinform News Agency reported.
Klitschko, 42, said from the Ukrainian parliament rostrum in the capital city of Kiev: "I want to say that I cannot be intimidated or stopped.
"In order to put an end to various attempts to get rid of me as a possible candidate, I want to say that I'm running for president."
With a professional boxing record of 47 wins (41 KOs) and two losses, the 6-foot, 7½-inch heavyweight is the leader of the Ukrainian Democratic Alliance for Reform party.