Clashes have erupted between Ukrainian protesters and riot police outside city hall in Kiev.
The clashes follow a night of scuffles and a stand-off after police moved in on a large protest camp in Independence Square.
But more demonstrators have joined the protest in response to an opposition call for solidarity.
The government’s decision to withdraw from a free-trade deal with the EU last month sparked huge street rallies.
Police stormed city hall as they tried to dislodge protesters from the building.
Reports said protesters used hoses to fire icy water back at the police.
Protesters gathered around the police, chanting slogans against their action, said 5 Kanal TV station in scenes carried on a live feed from the protests.
Police had moved in on the protest at about 02:00 a.m., saying they wanted to free up a passage through the square for traffic.
Protesters in hard hats locked arms to form human walls to try to resist the police push. At least nine people were detained.
There were calls for restraint from priests intoning prayers and pop singer Ruslana – urging “Do not hurt us!” – on a stage in the square. More people flooded into the square in response to pleas for solidarity.
The latest police action comes after EU foreign policy chief Catherine Ashton held talks with President Viktor Yanukovych on Tuesday.
Baroness Catherine Ashton, who was cheered by crowds when she visited Kiev’s main protest site, said she was saddened that police had later used force to try to remove protesters.
“I was among you on Maidan [Independence Square] in the evening and was impressed by determination of Ukrainians demonstrating for European perspective of the country,” Catherine Ashton said in a statement posted on Facebook.
“Some hours later I observe with sadness that police uses force to remove peaceful people from the centre of Kiev. The authorities didn’t need to act under the coverage of night to engage with the society by using police.”
Riot police and interior ministry officers dismantled some barriers and tents but met resistance from opposition supporters.
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