Ukraine's festering political crisis has turned deadly, with at least nine people reported killed and scores injured in violent clashes between anti-government demonstrators and police in Kiev.
he government shut down subway stations in the centre of the capital and threatened to restore order, but an evening deadline passed with no immediate police action.
Two policemen died, probably from gunshot wounds, as well as seven civilians, including three who were shot, Kiev city police spokeswoman Olha Bilyk told the Associated Press.
The clashes outside parliament erupted after the opposition accused the government of ignoring its demands in the nearly three-month-long protests.
As darkness fell, opposition leaders warned that security forces may be preparing to clear a sprawling protest tent camp on Kiev's Independence Square.
Thousands of protesters streamed to the square to defend the camp, where Orthodox priests prayed for peace.
"We see that this regime again has begun shooting people; they want to sink Ukraine in blood. We will not give in to a single provocation," opposition leader Arseniy Yatsenyuk told the protesters. "We will not take one step back from this square. We have nowhere to retreat to. Ukraine is behind us, Ukraine's future is behind us."
Shouting "Shame!", thousands of angry protesters hurled stones at police and set trucks blocking their way on fire. Riot police retaliated with stun grenades and fired what appeared to be small metal balls, as smoke from burning tyres and vehicles billowed over Kiev.
The clashes dimmed hopes for an imminent solution to the political crisis - and tensions also soared following new steps by Russia and the European Union to gain influence over the former Soviet republic.
The protests began in November after president Viktor Yanukovych froze ties with the EU in exchange for a 15 billion dollar (£8.9 billion) bailout from Russia, but the political manoeuvring continued and Moscow later suspended its payments. On Monday, however, while opposition leaders were meeting with German chancellor Angela Merkel, Russia offered a fresh infusion of the billions of dollars that Ukraine needs to keep its ailing economy afloat.
US ambassador Geoffrey R Payatt called for dialogue, but 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," Mr Payatt said on Twitter.