A 14-year-old was among those killed in clashes between protesters and police in the city of Suez.
The officials in the Suez Canal city identified the teenager as Mahmoud Issa
At least 186 people were injured in clashes around the country, according to the head of the country’s ambulance services, Mohammed Sultan.
The clashes came as the country’s mainly liberal and secular opposition held rallies across much of Egypt saying the goals of the 2011 anti-Mubarak pro-democracy uprising have not been met and denouncing Islamist president Mohammed Morsi.
Street battles also broke out in Ismaila, where the Muslim Brotherhood’s political party offices were torched.
Thousands of opponents of Morsi and his Brotherhood allies massed in Cairo’s Tahrir Square — the cradle of the uprising against Mubarak — to revive the demands of a revolution they say has been betrayed by Islamists.
The Jan 25 anniversary showcased the divide between the Islamists and their secular foes that is hindering Morsi’s efforts to revive an economy in crisis and reverse a plunge in Egypt’s currency by enticing back investors and tourists.
Motivated by Tunisia’s popular uprising, Egypt’s revolution spurred further revolts across the Arab world. However, the sense of common purpose that united Egyptians two years ago has given way to internal strife that has only worsened and last month triggered lethal street fights.
Police battled protesters who threw petrol bombs and firecrackers as they tried to approach a wall blocking access to government buildings near Tahrir Square.
Clouds of tear gas fired by police filled the air.
Clashes between stone- throwing youths and the police continued in streets around the square into the day. Ambulances ferried away a steady stream of casualties.
“Our revolution is continuing. We reject the domination of any party over this state. We say no to the Brotherhood state,” said Hamdeen Sabahy, a popular leftist leader.
There were similar scenes in Suez and Alexandria, where protesters and riot police skirmished near local government offices.