Whoever fired the first shots early Monday morning near the Presidential Guard barracks in Cairo has a lot to answer for – not just to Egyptians but to the whole region.
An estimated 54 people were killed and more than 400 wounded when military troops fired on a group of Islamist protesters. At least one of the dead was a soldier, the rest were members of a pro-Muslim Brotherhood group that has been camped outside the barracks for almost a week, protesting the ouster as president last Wednesday of Mohammed Morsi, a leading member of the Brotherhood who had been elected to office a year ago.
Egypt's military says its soldiers fired on the protesters only after their forces were fired upon by "an armed terrorist group" attempting to storm the barracks where Mr. Morsi is believed to be held in custody.
The Muslim Brotherhood, on the other hand, says its protesters were performing the pre-dawn prayer when security forces opened fire on them, unprovoked.
A lot is riding on the truth – including the viability of an interim government to run the country until new elections can be held, and the regional reputation of the Muslim Brotherhood as a moderate, non-violent Islamist movement.
For the most part, the Brotherhood's protests over the past 10 days have been peaceful, though individual supporters appear to have carried out some particularly violent acts. In one incident, the video of which has gone viral, apparent Brotherhood supporters were recorded throwing two anti-Morsi protesters off a platform onto the roof of a building in Alexandria, then beating them.
In running battles on Monday that followed the initial outbreak of shooting, at least one Brotherhood supporter was seen firing a handgun while several were captured throwing gas bombs and even spears from a rooftop.
"There's a limit to patience," said military spokesman Ahmed Ali in a statement to the press. "Tampering with Egyptian national security will not be allowed," he said, stressing that the military had repeatedly warned against attacks on its installations.
Last Friday, however, the military appeared to overreact when it opened fire on protesters outside the same Presidential Guard facility, killing three. The dead and wounded had reportedly only crossed the street in the direction of the soldiers and fired nothing but verbal abuse at the troops.
In response to Monday's deaths, the Brotherhood's political arm, the Freedom and Justice Party, called on Egyptians "to rise up against those who want to steal their revolution with tanks and armoured vehicles."
Later, the group dialled down the counterattack it sought, calling only for mass protests across Egypt on Tuesday.
A palpable tension has gripped the capital.
Sheik Ahmed el-Tayeb, the grand imam of Al Azhar, the most senior religious official in the country, made an unusual public appeal Monday. In a mid-afternoon broadcast on state radio and television, he called on authorities to quickly find the answers as to who was responsible for the deadly incident and urged all citizens to go home. The streets were not safe, he seemed to be saying. Most people followed his advice and the downtown had little traffic by late afternoon.
One Muslim Brother, Tharwat Abdel Salam from Alexandria had perhaps the best explanation for how events unfolded early Monday morning.
He described how the protesters, himself included, had been outside the military compound praying with their back to the soldiers, when they heard shooting to their right. "Not from inside the compound," he made clear. "From outside," he said, meaning from the protesters' side.
"No one was hit," he said. "They seemed to be firing in the air," whoever it was.
Similar shooting could then be heard to the left, also coming from outside the compound.
Only after that did the soldiers react, first by firing tear gas, then rubber bullets and, eventually, live rounds.
Mr. Salam's candid admission that the first shots came from outside the compound could explain why the military thought it was under attack, even if the shooting was not directed at the soldiers.
"But if they thought they were under attack, why didn't the soldiers fire in the direction of the shots?" asked Mr. Salam, dressed in a brown galabia and tan-coloured skull cap. "Why did they fire at us at prayer?"
In protest to the killings, the Islamist Nour party, the only Islamist group that backed military intervention against Mr. Morsi last week, announced it was withdrawing from talks about forming an interim government.
"The reason why we accepted to be part of the political scene is to stop the bloodletting and there's no point of our participating in political talks with the bloodshed now," Shaaban Abdel Alim, assistant secretary-general of the Nour party, told Bloomberg News. "The party is still considering its next steps."
Amr Mousa, a former Egyptian foreign minister and presidential candidate last year, said he regrets the Nour party's decision to withdraw from government talks.
"I hoped the Nour would have stayed," he said. "It is an important party with a lot of followers. … And it's important to have their support for an interim government."
That's one reason why it's necessary to find out who fired the first shots, Mr. Mousa said. "If videos show the army did come under attack, then the Nour party will have no reason to stay outside the talks."
And if the Brotherhood protesters did fire first, it will have set back the group's reputation for moderation immeasurably.