Russia has said it fears events in Ukraine’s capital Kyiv could be spinning out of control, as anti-government protesters continue a tense stand-off with police following Monday night’s violence.
The Foreign Minister Sergei Lavrov urged European governments not to interfere in the crisis.
It came hours before new regulations were due to come into effect in Ukraine, designed to clamp down on demonstrations.
They are part of a package of measures rushed through which some experts warn are too vague.
“All the definitions we do have in this set of regulations are very much unclear, what is extremism, what is political activity, what is a foreign agent. No lawyer in the country could give you a clear understanding of what these laws are about,” said Roman Romanov, Rule of Law Director at the International Renaissance Foundation.
A group of alleged provocateurs was paraded around the central square by protesters before being escorted out.
One opposition leader has accused the government of paying thugs to discredit the demonstrators by causing trouble.
Two opinion polls in Ukraine have suggested around half of people support the protesters, with just over a quarter backing the government.
“I am outraged, as the biggest part of the population of Ukraine, since the laws infringe our civil rights and these laws are anti-democratic,” said one woman in Kyiv.
“The word ‘freedom’ ceases to exist in Ukraine. Restrictions are being forced upon us that we don’t want to tolerate,” added a young man.
In the western city of Lviv, hundreds of activists blocked military units in an attempt to stop them from travelling to Kyiv. Similar scenes were said to be happening in other towns.
Euronews correspondent Sergio Cantone in Kyiv said: “The government should probably start reconsidering its decision (over the new regulations), because although it does concern the rule of law, in this case it also has huge political significance.”