Reasons for political crisis in Ukraine

The protests began in November as a pro-Europe gesture, underscoring the tensions in a country split between pro-European regions in the West and a more Russia-oriented East.

Thousands spilled onto the streets after President Viktor Yanukovych did a U-turn over a trade pact with the European Union that had been years in the making -- favoring closer relations with Russia instead.

Angered by this backpedaling, the demonstrators demanded the EU deal be signed, saying it would strengthen cooperation with the bloc.

Their daily protests soon escalated, drawing parallels to Ukraine's 2004 Orange Revolution, which toppled the government.

But with Ukraine desperately in need of a cash injection, Kiev cited the need for financial assistance if it were to do business with the EU. Yanukovych, in power since 2010, said Ukraine could not afford to sign the deal, alluding to economic pressure from Russia.

Another factor in Yanukovych's decision not to sign the deal is likely to have been the EU's demands that he free from jail former Prime Minister Yulia Tymoshenko, his political opponent. The Orange Revolution that swept him from office in 2004, when he was prime minister, also swept Tymoshenko to power.

Soon afterward, he flew to Moscow where he and President Vladimir Putin announced Russia would buy $15 billion in Ukrainian debt and slash the price Kiev pays for its gas.

While unhappy with that, what inflamed the demonstrators even more, however, was the adoption of a sweeping anti-protest law by the parliament on January 16.

The new law included provisions barring people from wearing helmets and masks to rallies and from setting up tents or sound equipment without prior police permission.

This sparked concerns it could be used to put down demonstrations and deny people the right to free speech -- and clashes soon escalated.

Last week, several people were killed and hundreds of others injured in heavy street fighting.

The epicenter of the protests has been Kiev's central Independence Square, Maidan, but the demonstrators have also blocked other streets and government buildings. On Sunday, they briefly seized the justice ministry.

"The changes that occurred after the Orange Revolution weren't simply deep enough. This time around, it appears that the disenchantment is so strong that there is a genuine opportunity to make a fresh start," said Dalibor Rohac, policy analyst with the Cato Institute's Center for Global Liberty and Prosperity.

"For Ukrainians this is a chance to get on a different trajectory from the one the country has been on for the past 22 years and become eventually a part of prosperous, democratic Europe."