The conservative Islamist party of ousted Egyptian President Mohamed Morsi called for a "day of rage" in Egypt on Friday, which could further exacerbate the ongoing turmoil there that has led to at least 600 deaths.
The Muslim Brotherhood has staged protests this week in and around Cairo, clashing with police and other security forces. Activists have torched government buildings and targeted some mosques and Christian churches.
The government authorized the use of deadly force in an attempt to quell the violence, while many world leaders press for a peaceful resolution to end the cycle of escalation.
A Marine Corps spokeswoman confirmed Friday that the 26th Marine Expeditionary Unit, 2,000 Marines aboard the USS San Antonio, remains in the northern Red Sea ready to respond to any emergencies or other contingencies.
The continued violence follows an announcement Thursday from President Barack Obama that the U.S. would cancel Operation Bright Star, a biennial exercise that has not taken place since 2010. The 26th MEU was scheduled to participate in the exercise.
"It signals the U.S.'s strong objection to recent events, including violence against civilians," Pentagon spokesman George Little said Thursday afternoon of the decision to cancel the exercise. "It's a clear signal to Egyptian authorities that we are deeply concerned about events in the country."
Obama made the decision to cancel on Wednesday, Little said, adding that the U.S. cabinet officials and other senior leaders expect to maintain continued contact with their Egyptian counterparts.
"These are Egyptian decisions, not American decisions," Little said.
At least 638 were killed and roughly 4,000 people were wounded on Wednesday, the deadliest day in Egypt since the 2011 Arab Spring revolution that lead to the dissolution of Hosni Mubarak's autonomous reign. Democratically elected Morsi was forced from office in early July following military action, though the U.S. has not yet classified that incident as a coup d'etat.
"I deeply feel the pain for every single Egyptian that was killed," said Turkish President Abdullah Gul on Friday, following reports that Turkey was withdrawing its ambassadors from Egypt. Turkey strongly backed the Morsi presidency and has denied accusations that it is meddling in Egyptian affairs.
"Turkey's warnings should be seen not as meddling in internal affairs, but as the sadness felt by a friend, the shock it experienced and as efforts to draw attention and to help," Gul said.
Egypt's goverment has declared a state of emergency and installed a curfew between 7 p.m. and 6 a.m., which a majority of protesters have ignored.
The U.S. Embassy in Egypt warned Thursday against American citizens' traveling to and within Egypt due to the continuing protests.
"Political unrest...shows little sign of abating," the embassy stated in the warning, citing the violence stemming from the constitutional referendum in December 2012, the anniversary in 2013 of Egypt's 25th of January Revolution and the July "change of government."
"Demonstrations have, on numerous occasions, degenerated into violent clashes between security forces and protesters, and between protesters supporting different factions, resulting in deaths, injuries, and extensive property damage," according to the warning. "Participants have thrown rocks and Molotov cocktails and security forces have used tear gas and other crowd control measures against demonstrators. There have been instances of the use of firearms as well."
Protests began in and around Egypt and nearby Giza and Alexandria, though the warning says they are slowly spreading into other corners of the nation.
"Of continued concern is gender-based violence in and around protest areas where women have been the targets of sexual assault," it says.