At least 51 people were killed and about 270 injured in clashes between Egypt's security forces and supporters of the Muslim Brotherhood (MB) Sunday, official news agency MENA reported, citing the health ministry.
Clashes erupted between the security forces and the MB supporters during the nation's celebrations of the 40th anniversary of Oct 6 war against Israel, Xinhua reported.
"One was killed in Menya governorate and another three were killed in Beni Sweif governorate, while most of the deaths were in Cairo and Giza," Khaled al-Kahteeb, chief of the central administration for emergency, told MENA.
The security forces fired tear gas to disperse MB supporters who tried to storm the Tahrir Square in an attempt to clash with thousands of pro-military people who gathered in the square to celebrate the anniversary.
Tahrir Square, the epic centre of the 2011 unrest that toppled former president Hosni Mubarak, was sealed off with tanks and barbed wire to prevent Morsi's supporters from entering it.
All the entrances to the square were blocked except for Abdel Moniem Reyadh which was open to the people coming for celebrations. People had to wait in long lines for security check to enter the square.
Inside the square, people waved national flags, with military planes hovering above. State-run media and some private networks aired national songs round the clock along with documentaries of the war that glorify the military.
They chanted for the army, holding pictures of Defence Minister Abdel Fattah Sisi who led the overthrow of Morsi in July, and late president Anwar Sadat who headed the Egyptian army in October 6 war.
Clashes erupted on Ramses street in Cairo, with security forces and residents of the area on one side and the Muslim Brotherhood supporters on the other. Hundreds of pro-Muslim Brotherhood protesters tried to reach Tahrir Square through Ramses street.
The interior ministry warned on Saturday of "attempts that may disturb the October 6 celebrations in Egypt."
Sunday's death toll was the highest in clashes between Islamists and police since the crackdown on Morsi's supporters Aug 14, when more than 850 people were killed, most of them Islamists.
Security forces arrested about 17 MB supporters carrying explosives who tried to block the metro line, state-run al-Ahram newspaper reported on its website.
The interior ministry said in a statement that police arrested 423 protesters in Cairo and Giza, accusing them of "firing live rounds and birdshot".
The Muslim Brotherhood said on its website that nearly 3,500 people have been jailed.
