Egypt's interim president Adli Mansour has called for
calm amid reports that 51 people were killed in clashes outside the
headquarters of the Republican Guard in Cairo.
Supporters of former President Mohamed Morsi claim they were protesting
peacefully outside the army premises when troops decided to open fire,
killing dozens.
But the military says supporters of Mr Morsi - who the Muslim
Brotherhood believes is being held inside the headquarters following his
ouster last week - attacked the premises with "heavy gunfire" first.
Sky News has obtained video footage which appears to contradict the
military's claims that it was attacked at the gates of the barracks by
the protesters.
The footage shows troops firing tear gas at demonstrators in the street.
The sound of automatic gunfire can also be heard, before troops surround a dead or wounded protester.
The footage also shows a man being beaten by army troops. The Muslim
Brotherhood's political wing has called for an "uprising" in the wake of
the violence.
As the two sides argued over who was to blame for the clashes, Egypt's
military released footage it says shows demonstrators shooting at
troops.
The footage - edited and released by the military - highlights at least two protesters who appear to be firing at the army.
Speaking at a news conference in Cairo, Army Colonel Ahmed Mohammed Ali
said two policemen and an army officer were killed in the incident,
adding that another 42 troops were injured.
Egypt's emergency services say at least 51 people died, and a further 435 people were injured.
Mr Mansour has called for restraint and ordered a judicial inquiry into the clashes.
A statement released by his office echoed the military's version of
events, noting that the deaths followed an attempt to storm the
Republican Guard's headquarters by protesters.
Some witnesses, including Brotherhood supporters at the scene, said the
armed forces fired only warning shots and tear gas, and that "thugs" in
civilian clothes approached from the side before carrying out the
deadly shooting.
"The Republican Guard fired tear gas, but the thugs came from the side.
We were the target," said Mahmud al Shilli, a Muslim Brotherhood
protester.
"I saw with my own eyes the people who they shot at," another protester said, adding that several people had been injured.
Speaking to Sky's Sam Kiley, one witness said Mr Morsi’s supporters
were attacked from the side and that the army fired the first shots.
"They fired tear gas and live bullets, we saw several people drop dead in the street. The attack came from the other side.
"(The protesters) were not doing any harm. They were just making some
prayers and singing songs; many of them are from outside Cairo.
"I saw two guys drop on the floor, I don't know if they were dead or
not. There were live bullets because we have learnt to know the sound of
live bullets as opposed to pellets."
Egypt's ultra-conservative Islamist Nour party said it had withdrawn
from negotiations to form a new interim government "in response to the
massacre outside the Republican Guard headquarters".
The armed forces overthrew Mr Morsi last Wednesday, backed by massive
street demonstrations. Muslim Brotherhood supporters have been staging
daily protests ever since.
Britain has called for movement toward free and fair elections and
agreement on a democratic constitution, and called on Egyptian
authorities to carry out an investigation into the events that led to
the deaths.
The European Union condemned the killings and said it was keeping its
billions of Euros in aid pledged to the country "under constant review".