> Officials however said, an armed group had taken to the rooftops and fired on both citizens and security forces.

This is the key. Immidiately peacefull demonstration became chaos and revolution with firearms. As they were ready and needed trigger. "Evil dictator, killing it's own people" (tm). This is the key. This is how revolutions are made today.
Don't you see it? Nobody found so called "ukranian snipers".