The Egyptian army threatened on Monday to intervene in the country's widespread protests if they do not stop in the next 48 hours. Earlier on Monday, protesters in Cairo stormed the headquarters of the Muslim Brotherhood, President Mohamed Morsi’s party, as the demonstration against Morsi’s government grew to the largest crowds since the 2011 revolution. No one was in the building at the time. Millions are estimated to have joined in the demonstrations across the country that coincided with the first anniversary of Morsi’s inauguration, and eight were reportedly killed on Sunday. Tamarod, the main opposition group, issued a statement demanding Morsi’s resignation—and said he would face a campaign of civil disobedience if he did not step down.