Bahrain has executed three Shia men who were convicted of killing three police officers in a bomb attack in March 2014. They were killed by a firing squad today. Hundreds took to the streets to protest yesterday when reports emerged online of their impending execution. <br/><br/>It is the first execution to be carried out in Bahrain since a 2011 uprising, led by the country's Shia majority, calling for greater political rights. The Sunni-ruled kingdom has escalated a crackdown on its Shia critics over the past year, including revoking the citizenship of the country's most prominent Shia Muslim cleric.