At least 28 people are reported killed and dozens more wounded in clashes between security forces and supporters of ousted Egyptian President Mohamed Mursi.
Violence flared as Egypt marked 40 years since its attack on Israel in the 1973 war.
Mursi’s Muslim Brotherhood used the anniversary to protest against the military which deposed the Islamist leader in July. Many people are said to have been arrested.
This was the latest bloody encounter between pro- and anti-Mursi forcest. Clashes on Friday killed at least four people.
Security around Tahrir Square in Cairo was tightened as those supporting the military gathered for the official celebrations.
The Brotherhood accuses the army of staging a coup and sabotaging democracy by removing Mursi, Egypt’s first freely-elected president. But those backing army chief General al-Sisi, believe Mursi was trying to acquire sweeping powers and mismanaging the economy – claims he denies.
On what should have been a day of unity, Egypt remains divided.