Police officers fired several tear gas canisters and flash grenades late Wednesday to disperse protesters in Iowa City who were advancing toward Interstate 80. Hundreds of protesters were met by a line of Iowa State Patrol and Iowa City police officers on Dubuque Street blocking their path to the busy highway. Reports say that a speaker identifying himself as a patrol officer ordered the crowd to disperse and warned that the failure to do so would result in the deployment of chemical munitions. Moments later, officers fired tear gas canisters when the crowd continued marching north. In the following minutes, the crowd backed up, attempted to rally and again march forward, but eventually were forced back.