Construction workers on strike stand outside the Rio 2016 Olympic Park construction site in Rio de Janeiro April 8, 2014. Workers building Rio's 2016 Olympic Park fought with security guards on Monday but although shots were fired no one was injured in the melee, eyewitnesses said. Scuffles broke out between guards and construction workers on strike for more pay and better union representation. The workers closed several busy avenues around the site on Monday and trouble ensued. [Photo/Agencies]