At least 51 people were killed during nationwide protests in Egypt that turned violent on Sunday. The Associated Press reports that 30 of the deaths occurred in Cairo. The protests continue following a military coup in July that forced out elected president Mohammed Morsi and marked the start of a crackdown on the Muslim Brotherhood.
Sunday was also a national holiday that marked the 40th anniversary of the start of Egypt's 1973 military conflict with Israel. Given the occasion, the military stepped up security around Tahrir Square which has served as the flashpoint of much of the Egyptian protest movement. According to USA Today, "Tanks surrounded the square as thousands of people converged, waving Egyptian flags and cheering on military helicopters and jets flying above as part of the celebration."
The Interior Ministry reported 423 arrests and said that the protests were intended to "ruin the celebrations and cause friction with the masses." On Saturday, Egyptian officials made the distinction that any protesters on Sunday would be treated not as activists, but as agents of foreign powers.