Protesters angry over a controversial energy project turned their aggression against military units on parade for the traditional May 21 celebrations in Chile. In a shameful ambush, protesters started throwing rocks at naval and army cadets, marching bands and other personnel who clearly have nothing to do with the energy project. HidroAysen is a major dam to be built in an ecologically sensitive area of southern Chile. The May 21 attack followed an incident in which a group of police officers, clearly not equipped for a mob, was attacked with Molotov cocktails and assorted objects, leaving one cop in serious condition (see video). The government temporarily banned the use of tear gas to break up rioters, in response to complaints that the gas may cause health hazards. The ban lasted all of three days, as the government announced that studies found the gas to be perfectly safe.