In Pictures: Kiev violence | Gallery

Demonstrators armed with flares and fire extinguishers battled with riot police on the streets of Kiev.

President Viktor Yanukovych, who has been wrestling with nearly two months of opposition protests, signed off on Friday on tough new laws introducing jail time and corrective labour for those occupying public buildings or disseminating slander on the Internet.

Protesters have thrown stones and Molotov cocktails, with police retaliating with flash grenades, tear gas and rubber bullets. Dozens have been wounded in the clashes.

Vitali Klitschko - the former heavyweight boxing champion who left the sport to pursue the presidency of Ukraine - tried to calm mobs of people but was sprayed with a fire extinguisher and forced to retreat.

Opponents of Yanukovich have announced a plan to gather people(***)s signatures expressing no confidence in his leadership and that of parliament.

A protester holds a photo of jailed opposition leader Yulia Tymoshenko, who accused her arch-rival Yanukovych of seeking to establish a ‘neo-dictatorship’, and urged people to mount a strong response.

Boxer-turned politician Vitaly Klitschko is the strongest potential challenger for the presidency.

Tens of thousands of people have taken to the streets and set up a permanent encampment in Independence Square.

The sweeping new laws ban any unauthorised installation of tents, stages or use of loud-speakers in public places.

The new laws were denounced by the United States and other Western governments as anti-democratic.

Yanukovich triggered rallies when he ditched a free trade deal with the European Union last November in favour of closer economic ties with Russia.

Many of the protesters were wearing pots and pans or construction helmets on their heads for protection.