Islamist supporters of ousted Egyptian president Mohamed Morsi challenged the military Saturday with a call for demonstrations on the 1973 Arab-Israeli war anniversary after the deadliest violence in weeks.
The Anti-Coup Alliance of Islamist groups called on its supporters to try once again to reach Cairo's Tahrir (Victory) Square, blocked off by the army, to mark Sunday's 40th anniversary of the war.
The conflict, known as the October war in the Arab world and the Yom Kippur war in Israel, is remembered proudly by the Egyptian army as it caught Israel's defences unawares and led ultimately to Egypt's recovery of the Sinai Peninsula in the 1979 peace treaty.
"The Egypt Anti-Coup Alliance repeats its call to all Egyptians to continue their protests in every part of Egypt, and to gather in Tahrir Square on Sunday, October 6, to celebrate the army of that victory and its leaders," the Islamist bloc said.
Attempts on Friday by Islamist protesters against the army's July 3 overthrow of Morsi to reach Tahrir Square sparked clashes with security forces who responded with tear gas and warning shots.
Four people were killed in Cairo's deadliest protest violence in more than a month as demonstrators clashed with coup supporters as well as security personnel.
It was unclear whether the dead were Islamists or their opponents. A senior medical official said only that none of them were security personnel.
Clashes were also reported in Alexandria and the Upper Egypt province of Assiut, state media reported.
Analysts said the Islamists' call for rival commemorations of the 1973 war marked a high-risk attempt to strip the current high command of the conflict's legacy of patriotic pride in the army.
"They will try to show that the present army is not the army of all Egyptians, but only of those who backed the coup," said Hassan Nafaa, professor of political science at Cairo University.
"But this message will not go down well," he told AFP.
Nafaa said the Islamists mistakenly believed they could repeat the 2011 protests that swept away veteran strongman Hosni Mubarak and his despised police.
"The Muslim Brotherhood fails to realise that there can't be another revolution," he said.
"Egyptian people are not against the army as they were against the police in January 2011. If there is violence tomorrow, the Muslim Brotherhood will be the loser".
The Anti-Coup Alliance said that Friday's bloodshed, which it blamed on "attacks on marches and protests," would only "increase our determination to continue the revolution".
But the Egyptian press blamed the Brotherhood for the violence and expressed concern that Sunday's demonstrations would see more.
"Muslim Brotherhood's bloody rehearsal for October 6," ran the headlined in independent daily Al-Masry Al-Youm.
Both the United Nations and the United States also voiced alarm at the violence and made fresh pleas for peaceful protests.
The protesters "have a responsibility to protest peacefully, to not incite violence, to not undertake violence of their own," said deputy US State Department spokeswoman Marie Harf.
In New York, UN chief Ban Ki-moon stressed "the importance of peaceful protest, respect for freedom of assembly and commitment to non-violence," his spokesman Martin Nesirky said.
The alliance led by the banned Muslim Brotherhood has desperately sought to keep up the momentum of its protests against the military-installed interim government.
But its ability to mobilise large crowds has been sharply reduced by the rounding up of nearly all of its leaders.
More than 2,000 Islamists have been detained since security forces cleared their two main Cairo protest camps on August 14 in an operation that left hundreds dead.
An Egyptian court has also banned the Brotherhood from operating and has seized its assets.
Morsi, Egypt's first democratically elected president, was overthrown by the army following mass protests against his single year in office. He has been held at an undisclosed location ever since.