At least 44 people were killed in Egypt Sunday and 100 wounded in protests marking the 40th anniversary of the 1973 Yom Kippur War with Israel, a security source said.
Fighting began after supporters and opponents of deposed Egyptian President Mohamed Morsi of the Muslim Brotherhood took to the streets. Most of the dead had gunshot wounds, on the commemoration of the 40th anniversary of the nation's last war with Israel, security sources said.
Supporters of deposed Islamist President Mohammed Morsi had been marching in Delga, about 300 km south of Cairo, when the clash erupted as protesters neared a police station, the sources said.
The security and medical sources said the protesters threw stones at police who responded with live fire. It was not immediately possible to verify what started the clash.
Egyptian jetfighters staged celebratory flights over Cairo Sunday, ushering in the commemoration of the 1973 war on a day when rival rallies by supporters and opponents of the ousted Islamist president carry the potential for violence.
Security forces are deployed across much of the Egyptian capital in anticipation of clashes. Local media reported that checkpoints on all access roads to Cairo and key state institutions were manned by soldiers.
Sunday's rallies in Tahrir Square, birthplace of the 2011 uprising against autocrat Hosni Mubarak, were likely flashpoints. Authorities have vowed not to allow supporters of the ousted Mohammed Morsi into the square.
The possibility of bloodshed on an occasion revered by most Egyptians is seen as a sign of the schism that began soon after Morsi's narrow election victory in 2012.
Barbed wire and barricades blocked traffic to the square as security personnel were deployed with sniffer dogs outside the nearby National Museum. Metal detectors were also installed at entrances to Tahrir to prevent weapons from being smuggled into the square.
An alliance led by Morsi's Muslim Brotherhood called for anti-military protests in Tahrir Sunday, which marks Army Day and the 40th anniversary of the Egyptian-Israeli war.
Hundreds of people have been killed in Egypt since Morsi's overthrow in clashes involving his supporters, opponents and security forces.
Morsi's Brotherhood and its Islamist allies have denounced the ouster of Egypt's first democratically elected president on July 3 as a coup, and vowed to continue protesting until he is reinstated.