Egypt’s Muslim Brotherhood called on masses to take to the streets for a Friday of Anger, raising fears of more violence as the death toll from clashes this week rose to 638 with another 2,000 injured. Security forces have been authorized to use live ammunition against mobs attacking public buildings. Violence on August 15 included attacks on security forces, the burning of government offices in Giza, and attacks on Christian churches across the country. UN officials noted with alarm Friday that Christian churches and institutions were at risk after being targeted in the provinces of Sssiut, Fayoun, Menia and Sohaq by Islamists venting their anger over incidents in Cairo.