Striking construction workers and security personnel clashed Monday at Rio de Janeiro's Olympic Park, the main cluster of venues for the 2016 Summer Games. Rio Mais, the consortium building the Olympic venues, confirmed that random gunshots were fired as workers and security confronted each other. There were no reports of injuries. Spokespeople from both Rio Mais and the Rio Olympic organizing committee said that they were investigating the incident. The work stoppage involving more than 2,000 workers began Thursday, and Rio Mais said that it was unclear when work would resume. The dispute is about which union represents the construction workers, as well as benefits and working conditions. The strike adds to the growing list of problems confronting Rio organizers with the games just over two years away.