Tear gas fired as hundreds protest against Iranian regime over the downing of Ukrainian plane. According to multiple reports, hundreds are rallying in the streets of the Iranian capital calling for the Supreme Leader Ayatollah Ali Khamenei to resign after the government acknowledged its military had mistakenly shot down a Ukrainian jetliner, killing all 176 people on board. Reports and videos from the scene appear to show security forces using tear gas on demonstrators in an attempt to disperse the crowds.