At Least five people were killed and scores injured as anti-government protesters fought riot police in Kiev.

Ukrainian police said five civilians had died in clashes.

Medics working at field hospitals run by the opposition had said earlier that three protesters died of gunshot wounds and around 150 others were injured - 30 seriously.

They said most of the injuries were caused by stun grenades and some had suffered head injuries, with one person having to have a hand amputated.

President Viktor Yanukovych's ruling Party of the Regions said an employee at its headquarters was also found dead after protesters briefly seized the building.

Several hundred attacked the building with Molotov cocktails and smashed their way inside, but later withdrew.

They set fire to lorries blocking a street near the parliament building and hurled paving stones and Molotov cocktails at police.

The riot squads retaliated with stun grenades, rubber bullets and smoke bombs as rioters tried to rush the heavily fortified parliament.

Security forces said 47 soldiers had been injured, including five with bullet wounds.

Riot police eventually succeeded in forcing protesters back into their camp on Kiev's Independence Square after heavy reinforcements arrived.

The confrontation came after parliament delayed discussing changes that would limit President Viktor Yanukovych's powers.

Around 20,000 protesters had marched from Kiev's Independence Square to parliament to demand a vote on the reforms.

The opposition demanded that Mr Yanukovych give in to their demands if he wanted to defuse the violence.

Elsewhere, Russia's Foreign Ministry lashed out at Western countries for turning a blind eye to radical elements inside the protest movement.

"What is happening is a direct consequence of the policy of connivance among Western politicians and European agencies that have been shutting their eyes to the aggressive actions of radical forces since the beginning of the crisis," it said.