Nearly 50 people have been killed in clashes between rival demonstrators on the third anniversary of the 2011 revolution that led to the ouster of long-time dictator Hosni Mubarak, overshadowing what the government had hoped would be remembered a day of nationalist celebration.
Rival demonstrations of supporters and opponents of the military-backed government took place in Cairo yesterday.
But police quelled anti-government protests, and arrests were reported in Cairo and Alexandria as violence broke out.
Forty-nine people were killed, the ministry said, in 24 hours of fighting across Egypt as police and supporters of the military-installed government clashed with Islamist backers of president Mohamed Morsi, who was deposed in July after a single turbulent year in power.
Most of the deaths were in Cairo and its suburbs, and others in Alexandria and Minya, while 247 were injured, the health ministry said today. Egypt's interior ministry announced that a further 1,079 people had been arrested.
Hundreds have died since July when the army deposed Morsi, the country's first democratically elected president of the Muslim Brotherhood.
Extra security measures were in place yesterday as Egyptian Interior Minister Muhammad Ibrahim urged Egyptians not to be afraid to go to events marking the anniversary of the uprising.
Thousands of supporters of the military and the government gathered in high-profile locations including Tahrir Square - the focal point of the 18-day popular revolt in 2011, the BBC reported.
Participants waved Egyptian flags and banners showing army chief Gen Abdel Fattah al-Sisi, whom many urged to run for president.
Meanwhile, four Egyptian soldiers were killed and 13 others injured when militants attacked their bus in the restive Sinai Peninsula today, prompting the military to threaten the complete elimination of members of the Muslim Brotherhood, which has been declared a "terrorist" group.
The attack took place 50 metres from a security checkpoint and comes a day after militant group Ansar Bayt Al-Maqdis claimed responsibility for bringing down a military helicopter in a rocket attack in North Sinai that killed its crew of five soldiers.
At least 18 people died in violence on Friday.
Three years on from an uprising that raised hopes of political reform in the Arab world's most populated country, rival demonstrations are showing the deep divisions.
The Brotherhood has regularly held protests since the overthrow of Morsi. Hundreds of its supporters have been killed, and thousands detained.