Prepare for another day of upheaval in Egypt.

Amidst news that the police were authorized to used deadly force to subdue protestors, the Muslim Brotherhood has called for a "day of rage" Friday. The Islamist group is rallying Egyptians to voice their anger over the government-authorized crackdown on protesters that killed more than 600 people and injured around 4,000. They are also asking for citizens to oppose the declared state of emergency and sundown curfew that the country is currently under.

The Brotherhood asked supporters to take to the streets for a march after Friday afternoon prayers, a time that has become synonymous with protestor demonstrations since the start of the Arab Spring in 2011.

On Wednesday, police raided two protestor camps, which were formed when the country's president was removed and replaced by a military-backed interim leader. Groups of former president Morsi's supporters had been living in the camps for about six weeks before Egyptian authorities moved in with riot police, bulldozers, armored cars, and tear gas, violently crushing the protestor settlements and causing the deadliest day since the 2011 overthrow of Hosni Mubarak.

On Thursday, the violence continued as government buildings were set on fire, police were targeted in shootings, and Christian churches attacked. A mob also attacked the governor's office in nearby Giza.

In response to this week's violence, President Obama announced the cancellation of joint military exercises with Egypt, which were scheduled for next month, saying, "While we want to sustain our relationship with Egypt, our traditional cooperation cannot continue as usual when civilians are being killed in the streets and rights are being rolled back." Obama did not announce any changes to the more than $1 billion in aid the U.S. provides to the country.

With violence expect to continue, the State Department issued a warning to U.S. citizens in Egypt telling them to leave the country.