Iraqi security forces opened fire, killing 18 people and wounding hundreds in the holy city of Karbala on Tuesday in one of the worst attacks since the country was engulfed by protests this month. AP reports the security forces were wearing masks and black plainclothes when they opened fire on hundreds of protesters. It came on the fifth consecutive day of protests against the Iraqi government’s corruption and lack of public services. Before the attack in Karbala, at least 72 protesters had been killed since the protests resumed Friday, and 149 were killed in an earlier wave of protests this month. In the Karbala attack alone, more than 800 people were reportedly wounded.