Anti-government protests in Ukraine's capital escalated into fiery street battles with police as thousands of demonstrators hurled rocks and firebombs and set police vehicles ablaze. Dozens of officers and protesters were injured.

Police responded with stun grenades, tear gas and water cannons, but were outnumbered by the protesters.

Opposition leader Vitali Klitschko tried to persuade demonstrators to stop their unrest, but failed and was sprayed by a fire extinguisher in the process.

President Viktor Yanukovych last week signed an array of laws severely limiting protests and banning the wearing of helmets and gas masks. Many of Sunday's demonstrators wore hardhats and masks in defiance of the new laws. They set several police buses on fire and some chased and beat officers.