Protesters — including many students — gathered in Iran on Saturday and Sunday, criticizing the government and demanding the country’s Supreme Leader Ayatollah Ali Khamenei step down. Iran initially denied involvement in the incident, but later said the Islamic Revolutionary Guard Corps, fearing retaliation from the U.S. for a strike Tuesday against an American military base in Iraq, mistook the plane for hostile aircraft and launched a missile that brought the plane down, killing everyone on board.

A candlelit vigil in Tehran for the victims Saturday evening morphed into a protest before police broke up the gathering with tear gas. Iranian security forces deployed in large numbers in Tehran on Sunday, patrolling the city on motorbikes and stationing at various landmarks in anticipation of more protests.