A group of 5,000 to 6,000 protesters left Kiev's Independence Square Monday morning and headed toward Ukraine's Cabinet of Ministers where they blocked the entrances to the building.
Protesters are requesting the resignation of the government and of Ukraine's president, Viktor Yanukovych, who last month halted preparations to sign a trade deal with the European Union.
The opposition is also demanding that early parliamentary and presidential elections be held.
Opposition leader and heavyweight boxing champion Vitaly Klitschko said on Sunday that the demonstrations would only end with the ousting of the current government.
Tens of thousands of protesters have remained on the streets of downtown Kiev, and those who remain on Independence Square have reinforced barricades around its perimeter using bits of Christmas tree and sections of skating rink barriers, among other things, Interfax reported Monday.
Protesters continue to occupy the city administration building and the trade union headquarters, though entrances to both buildings are open and people are coming and going freely, the report said.
On Sunday, 165 people were given first aid and 109 were hospitalized following protests on Independence Square, the Kiev City State Administration said on its website.
On Nov. 30, the Berkut, Ukrainian riot police units, violently dispersed crowds of protesters, sparking domestic and international outrage.
Ukrainian Parliament Speaker Vladimir Rybak said the government and the opposition needed to hold emergency talks in an interview on Inter, a Ukrainian television channel.