So, yeah. Things seem to be happening:
The 2013 Ukraine pro-European Union protests or EuroMaidan (Ukrainian: Євромайдан) protests in Ukraine began on the night of 21 November, 2013, when Ukrainian citizens started spontaneous protests in the capital of Kiev. On the previous day, on 21 November 2013, the Ukrainian government suspended preparations for signing an Association Agreement and Deep and Comprehensive Free Trade Agreement with the European Union. The protests are ongoing despite a heavy police presence, and an increasing number of university students are joining the protests. Law enforcement agencies, namely Berkut (a special unit of the Ministry of Internal Affairs), violently and without provocation attacked peacefully protesting students and journalists in the early morning of 30 November. The escalating violence from government forces has caused the level of protests to rise, with 350-700,000 protesters demonstrating in Kiev at the movement's peak on December 1.
On December 1, Kiev District Administrative Court banned further protests in downtown Kyiv on both Independence Square and European Square, as well as in front of the Presidential Administration and Interior Ministry buildings, until 7 January 2014. Opposition forces planned the rally on the 1st to take place at St. Michael's Square, which is not among the banned rally locations, with a march towards Independence Square. During the December 1 rally, protesters followed through and defied the ban and marched form St. Michael's Square to re-take Independence Square. Protesters broke several windows in the city council building, followed by crowds spilling out of Independence Square to the Administration of President building at Bankova Street and the Cabinet building (Hrushevsky Street). People chanted "Out with the thugs" and sang the Ukrainian anthem. The opposition party Batkivshchyna claimed as much as 500,000 protesters turned out for the rallies, and opposition leader Petro Poroshenko claimed 350,000 were on Independence Square. Other news agencies reported over 100,000 in Independence Square alone. Other reports indicated 300,000 to 700,000 demonstrators.
At around 14:00, a group of protesters commandeered a bulldozer from Independence Square and attempted to pull down the fence surrounding the Presidential Administration building. People threw bricks at Berkut guards. At least three people were injured outside of the presidential administration building, receiving head injuries from flying debris. AFP reporters saw security forces outside the Presidential Administration building fire dozens of stun grenades and smoke bombs at masked demonstrators who were pelting police with stones and Molotov cocktails.
Footage from yesterday:
Generally this seems to be presented as a conflict between pro-Russia (largely conservative) and pro-EU (largely liberal) factions.
Some commentary (though can't vouch for its accuracy): Who is behind the Ukrainian protest? A letter from Lviv