There have been fresh clashes between police and protestors in the Ukrainian capital Kiev.
It is understood the clashes were prompted after some protesters tried to enter the government building. Police responded with tear gas.
Hundreds of protesters have gathered on European Square again after tens of thousands of Ukrainians flooded the streets of Kiev yesterday in the biggest anti-government protest since the 2004 Orange revolution to demand president Viktor Yanukovych reverses a decision not to sign a key pact with the European Union.
The protests which may herald the most serious challenge to Mr Yanukovych’s authority since he came to power in 2010, ended with scuffles with police outside government offices.
Ukraine was to have signed a historic free trade and association deal with the EU at this week's Eastern Partnership summit in Vilnius, Lithuania. EU officials said Ukraine's abrupt U-turn came as a result of Kremlin pressure.
Russia's president, Vladimir Putin, wants Kiev to join a Moscow-led customs union. An estimated 45 per cent of Ukraine's population support closer ties with the west.
“We want to be in Europe” said 46-year-old Liudmyla Babych yesterday, a saleswoman from Kiev, holding a placard reading “Mr President – the Ukrainian nation will not forgive you this treason.”
She was one of thousands of people who held a peaceful meeting on European Square demanding Mr Yanukovych abolish the decree and sack the government.
But after the meeting, several hundred protesters rushed to the government headquarters demanding the government’s resignation and that of the presidential administration.
People threw smoke bombs and stones at police and shouted “Revolution!” Opposition politicians tried to calm the crowd but without success. The police responded by deploying teargas.
Many people came to Kiev from other regions. "We already were under Russian rule for hundreds of years," said Mykhailo Yaremchuk, a villager from the Vinnytsia region in Ukraine's north-west, holding up a banner calling for the release of jailed opposition leader Yulia Tymoshenko, whose imprisonment has been an obstacle to an EU-Ukraine deal. "I came here hoping that my children and grandchildren will live in Europe, that they will live a better life than I had."
In an address read by her daughter, Eugenia, Ms Tymoshenko said: “By mystical coincidence Yanukovych again brought us to the squares. We need to complete what we didn’t finish after Orange revolution back in 2004.”