NEW The Tamarod , or `` rebel , '' campaign , a large movement led by opponents of the president , has spent months collecting signatures on a petition calling for Morsy to step down and call new elections . : Three people are killed during Sunday clashes , a spokesman says . The Muslim Brotherhood reports its Cairo headquarters fall under attack . Large crowds of anti - Morsy protesters chant ` ` leave '' at protests . ` ` Either you back off , or the only thing left to do is strike with your fist , '' says a Morsy supporter .
NEW : Three people are killed during Sunday clashes , a spokesman says . The Muslim Brotherhood reports its Cairo headquarters fall under attack . Large crowds of anti - Morsy protesters chant ` ` leave '' at protests . ` ` Either you back off , or the only thing left to do is strike with your fist , '' says a Morsy supporter .