Election timetable revealed as nation reels Aftermath: A protester holds a bloodied Koran and shell casings after Monday's protest massacre. With Egypt still reeling from a deadly day of violence that has further inflamed Islamist supporters of ousted president Mohammed Mursi, the country's interim head of state has unveiled a swift transition timetable that could bring new elections within six months. Egyptians were still grappling with details of the mass shooting that left 51 supporters of Dr Mursi dead and more than 400 wounded. The shooting began at dawn on Monday outside the Republican Guard barracks where Dr Mursi is being held, when soldiers stationed inside the barracks opened fire on the large crowd of Muslim Brotherhood supporters while they were engaged in morning prayers. In the chaos of the next three hours, witnesses said police stationed outside the barracks also started shooting, firing tear-gas in an attempt to disperse the crowd. Many of the wounded were taken to the nearby Atamin Azahi hospital in Nasr City. "This was the bloodiest day in all my years as an orthopaedic surgeon at this hospital," Dr Haythem Awad said. I am sure that from the people I treated today, there will be more dead than they [the army] are admitting. At the scene of the shooting there were scores of bullet casings littering the footpath. One soldier was also killed, with military authorities maintaining the soldiers were acting in self-defence after the crowd of pro-Mursi supporters tried to storm the fortified barracks. A media conference about the shootings began in bizarre circumstances when journalists with Qatar's Arabic news channel al-Jazeera were ejected from the room to loud applause and cheers from the Egyptian press corps. Al-Jazeera, which has already been subjected to intense harassment from security services after last week's coup because the Qatari ruling family has been a strong backer of the Muslim Brotherhood, was the first channel to broadcast images of the massacre. The Egyptian press also cheered the police and army spokesmen as they attempted to blame the pro-Mursi protesters for the violence. In an attempt to reassure a shocked public and increasingly concerned international allies, late on Monday interim president Adli Mansour issued a decree setting a six-month timetable for new parliamentary elections to be soon followed by a presidential ballot. The elections will take place once amendments to the constitution are approved in a referendum. In what appeared to be an olive branch to Islamists, the decree included controversial language put into the constitution last year that defined the principles of sharia. Whether it will be enough to lure back the hardline Islamist Nour Party, which endorsed the military-led transition plans until Monday's attack, remains to be seen. The Brotherhood has refused to have anything to do with the process. The events have worried Western allies. The United Nations said it was "gravely concerned" about mounting violence in Egypt and said the country was on a "precarious path." "The Secretary-General condemns these killings and calls for them to be thoroughly investigated by independent and competent national bodies," the UN said in a statement. The US, still refraining from calling the military intervention a "coup" - a label that would trigger legal obstacles to continuing aid payments - called on Egypt's army to exercise "maximum restraint." The White House said it was not about to halt aid to Egypt.