A masked protester walks between burning barricades in Managua, Nicaragua, Friday, April 20, 2018. The clashes, pitting protesters opposed to social security reforms against riot police and pro-government groups, have rocked the capital, and a half-dozen other cities over the last three days. The Organization of American States have expressed concern over the heavy-handed crackdown, while also calling on demonstrators to protest peacefully. (AP Photo/Alfredo Zuniga)