Sporadic clashes between police and protesters have spread across Ukraine despite President Viktor Yanukovych announcing concessions to demonstrators to try to restore calm to the country.
Mr Yanukovych offered to reshuffle his government and to grant an amnesty to dozens of activists arrested during weeks of rioting that has left four protesters dead and dozens of police injured.
But within hours of his offer, the sky in Kiev was filled with black smoke as protesters set fire to barricades built with bags of ice, car tyres and furniture as opposition leader and former heavyweight boxing champion Vitali Klitschko said only Mr Yanukovych's resignation would mollify the protests.

President Viktor Yanukovych and opposition leader Vitali Klitschko Protesters wearing ski masks and armed with sticks hurled firebombs, rocks and fireworks at riot police while officers retaliated with tear gas and baton charges in a repeat of violent scenes earlier in the week that subsided after Mr Yanukovych began talks aimed at a truce.
"We will force the authorities to respect us," 27-year-old protester Artur Kapelan said. "Not they, but we will dictate the conditions of a truce."
The rallies in Kiev began in November last year after Mr Yanukovych scrapped a treaty with the European Union in favour of a bailout loan from Russia, following lobbying by Russian president Vladimir Putin.
Political activists began by calling for stronger unification with Europe rather than a new alliance with Russia but the protests have since evolved to call for Mr Yanukovych's resignation and the scrapping of harsh anti-protest legislation.
The fighting stopped earlier in the week after opposition and religious leaders began talking with Mr Yanukovych to find a political solution to the unrest.
The protest map tweeted by Swedish foreign minister Carl Bildt The president had offered to meet some of their demands as thousands of protesters laid siege to government buildings in several cities in the country.
But Mr Klitschko declared the protests would continue until Mr Yanukovuch offers to resign.
Reporting from Kiev, Sky's Katie Stallard said the protesters intend to hold their ground.
"The protesters insist the police fired first, they say that means this truce is off and they're returning fire with whatever they can find.
"They're sending fireworks up to the police lines and throwing Molotov cocktails towards them. The police lines are 40 metres in front of them, (the protesters) are up on top of burnt-out buses and waving the national flag.
"All the time tyres are being taken through to put on these flames. They're trying to build up as much smoke as they can to obscure their view.
"Behind them there are hundreds more here cheering them on behind the barricades, beating on whatever they can find. They're shouting 'glory to Ukraine' and they're determined to hold their ground."
Swedish foreign minister Carl Bildt suggested Mr Yanukovych was losing control over his country. He posted a map of Ukraine on Twitter showing which regions had succumbed to protests.
"If Kiev regime tries a military solution to this situation, it will be very bloody and it will fail," he tweeted.
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