The boy was shot and killed by birdshot rounds as he watched the confrontations from his balcony, security forces said.
Three supporters of deposed President Mohamed Morsi were arrested In Salamut, Ahram Online reported.
One person was killed in the city of Damietta in clashes that erupted after Morsi supporters attempted to organize a rally after Friday prayers, the news website Aswat Masyra reported.
Security was strengthened in Cairo and Giza before demonstrations by Morsi supporters against the interim government. Clashes occurred, with protesters throwing rocks at security forces, but no deaths or injuries were reported, Ahram Online said.
The National Alliance to Support Legitimacy, a coalition led by Morsi's Muslim Brotherhood, called for a new round of demonstrations Friday -- the typical day of protest in Egypt -- to mark six months since a deadly police raid on pro-Morsi protest camps in Cairo, Ahram Online said.
Egyptian security forces deployed armored vehicles and riot police to Cairo's Tahrir Square, ground zero for 2011 mass protests that toppled President Hosni Mubarak, the Middle East News Agency reported.
A crackdown on Morsi's supporters since his ouster has shrunk the size of the demonstrations, Ahram Online said. Thousands of Morsi supporters have been arrested and hundreds have been killed.