Security officials inspect the scene of a bomb blast that apparently targeted Egyptian Interior Minister Mohammed Ibrahim near his home in Cairo's Nasr City on Thursday. He survived the attack. Khaled Elfiqi /EPA/LANDOV hide caption

itoggle caption Khaled Elfiqi /EPA/LANDOV

Former Egyptian President Hosni Mubarak sits in the dock during a June 8 court hearing in Cairo. Amr Abdallah Dalsh /Reuters/Landov hide caption

itoggle caption Amr Abdallah Dalsh /Reuters/Landov

Egyptian soldiers stand guard in front of the constitutional court in Cairo. Al Youm Elsabaa newspaper /EPA/LANDOV hide caption

itoggle caption Al Youm Elsabaa newspaper /EPA/LANDOV

An Egyptian Apache helicopter flies over a crowd of pro-military demonstrators at Tahrir Square in Cairo on July 26. U.S. firms supply military hardware to the military, including the Apache helicopters. Ed Giles/Getty Images hide caption

itoggle caption Ed Giles/Getty Images

Former Egyptian President Hosni Mubarak sits in the dock during a court hearing in Cairo on June 8. Amr Abdallah Dalsh /Reuters/Landov hide caption

itoggle caption Amr Abdallah Dalsh /Reuters/Landov

In Cairo, soldiers have put barbed wire around the constitutional court, one of many government institutions under guard. Amina Ismail /MCT/Landov hide caption

itoggle caption Amina Ismail /MCT/Landov

Crowds gather around the burning headquarters of the Muslim Brotherhood in Cairo on Oct. 27, 1954. The building was set on fire following the attempted assassination of President Gamal Abdel Nasser. AP hide caption

itoggle caption AP

A man in Cairo who said he had been wounded by a rubber bullet Friday gets help. Andre Pain /EPA/LANDOV hide caption

itoggle caption Andre Pain /EPA/LANDOV

An Egyptian army soldier stands Thursday amid the charred remains of the Rabaah al-Adawiya mosque, in the center of the largest protest camp of supporters of ousted President Mohammed Morsi, that was cleared by security forces in Cairo on Wednesday. Hassan Ammar/AP hide caption

itoggle caption Hassan Ammar/AP

President Obama, speaking Thursday from the island of Martha's Vineyard, Mass., said the U.S. has canceled joint military exercises with Egypt. Jacquelyn Martin/AP hide caption

itoggle caption Jacquelyn Martin/AP

Posters of ousted Egyptian President Mohammed Morsi lay amid the rubble of a protest camp in Cairo after Wednesday's crackdown by government forces. Ahmed Assadi/EPA/Landov hide caption

itoggle caption Ahmed Assadi/EPA/Landov

Protesters taunt security forces moving in to clear one protest camp near the Rabaa al-Adawiya mosque in Cairo. The military-backed government described the camps as violent and unlawful. Hesham Mostafa/EPA/Landov hide caption

itoggle caption Hesham Mostafa/EPA/Landov