KIEV, UKRAINE - February 20, 2014: Medical staff work at an improvised field clinic in Maidan, during violent clashes with riot police over the control of Independence Square in central Kiev. The riot police responded to the advance with gunfire that, according to the opposition, killed at least 70 and as many as 100 people. The drastic escalation of the three-month-old Ukraine crisis left the country reeling from the most lethal violence in decades. CREDIT: Paulo Nunes dos Santos