Dozens of protesters were reported wounded in Ukraine's capital early Saturday when police brutally dispersed demonstrators calling for President Viktor Yanukovych's ouster after he failed to salvage an EU deal.
A rally of some 10,000 protesters led by top opposition leaders like world boxing champion Vitali Klitschko called Friday night for the president to step down after he refused to sign a key political and free trade deal with the European Union at a summit in Vilnius.
Around 1,000 protesters remained on the square overnight and riot police moved in around 4:00 local time, swinging batons and pushing protesters from the square, according to witnesses.
"The Maidan has been brutally mopped up," opposition lawmaker Andriy Shevchenko said on Twitter, referring to Kiev's central Independence Square, the site of the rally and the epicentre of the country's pro-Western 2004 Orange Revolution.
"Dozens wounded, dozens arrested. Ukraine has not seen anything like this before."
The US ambassador in Ukraine on Saturday condemned what he said was the use of violence against peaceful protesters.
"Still working to understand what happened, but obviously condemn the violence against peaceful demonstrators," Geoffrey Pyatt said on Twitter. "Will have more to say."
One of the protesters told AFP that the riot police moved in suddenly, without provocation, on peaceful demonstrators.
"We were dancing, jumping and crying out peaceful slogans," said one demonstrator, Maria Chalykh.
"They started beating everyone indiscriminately. They beat everyone, the elderly, girls, even a child. His entire face was covered in blood," the 17-year-old student told AFP.
"Everyone shouted, cried, some people fainted."
Chalykh said that the Berkut riot police dragged people, kicked them and swore at them.
She herself lost consciousness and came to in an ambulance, she said.
She estimated that several dozen people might have received injuries.
A police spokeswoman told AFP that 31 protesters had been detained for hooliganism and for resisting police and that most of them have been released.
The organisers of the rally set up a first aid station outside a church in the city centre.
Hundreds of riot police were deployed around the square in the run-up to Friday's rally, heightening tensions on day six of mass rallies against Yanukovych's decision to scrap the EU deal under Russian pressure.
Opposition parliament member Oleksandra Kuzhel vowed to go ahead with a protest planned for Sunday despite the violence.
"We are not going to retreat," she told AFP.
On Friday jailed opposition leader Yulia Tymoshenko, who had hoped to walk out of prison as a result of the EU deal, called on students to keep the protest alive.
"At stake is our life together," she said in a statement. "Just try to defend it like adults through all means possible."