When the U.S. Embassy here was besieged by protesters who took down the American flag and raised a black Islamist flag that looks similar to that of al-Qaeda, among the crowd was a man whom Western counterterrorism agencies are watching closely.
Mohammed al-Zawahri denies he is a member of al-Qaeda, but the younger brother of al-Qaeda's leader, Ayman al-Zawahiri, shares its goal of global Muslim theocracies based on strict religious law.
Jailed 13 years on militancy charges, he was freed following the revolution that ousted Egyptian dictator Hosni Mubarak, and he has a message to the United States.
"If America does not stop (its) violations or attacks, there will not be just one Ayman al-Zawahri, but all Muslims will (become like) Ayman al-Zawahri," he said in an interview with USA TODAY.
"Our sharia commands us to stick to peace, to stick to Islam, to build our civilization, but if someone attacks us, our religion commands that all of us turn to be jihadists."