Cairo, Egypt (CNN) -- All agree that scores angry at
 Egypt's military-backed government and the ouster of President Mohamed 
Morsy died in late-night clashes in the volatile nation's capital.
 Photos: Unrest in Egypt
Photos: Unrest in Egypt
 Pro- and anti-Morsy crowds flood streets
Pro- and anti-Morsy crowds flood streets
 Are oil prices and Egypt's chaos linked?
Are oil prices and Egypt's chaos linked?
 Tahrir Square filled at general's urging
Tahrir Square filled at general's urging
 
But they are of opposite minds as to who began firing first and who is to blame.
Dr. Mohammed Ali Sultan, 
chairman of Egypt's ambulance services, told CNN that 72 had been killed
 in Nasr City, an area of Cairo the Muslim Brotherhood has made its base
 after the group's former leader was forced from power and ordered 
jailed.
Medics in a Brotherhood 
field hospital there earlier Saturday had put the death toll at 66, with
 another 61 on life support and thousands more wounded.
How did they end up in such straits?
Ask the Muslim 
Brotherhood -- the Islamist group that was sidelined under longtime 
Egyptian leader Hosni Mubarak only to become the country's dominant 
political force after his forced exit in 2011 -- and its members will 
say police fired live ammunition on protesters Friday and Saturday.
A wounded protester 
getting medical treatment at a field hospital said he saw men in 
plainclothes fire on pro-Morsy demonstrators with shotguns.
He referred to them as "thugs," a term commonly used for young men who support the government and resort to violence.
"Police forces were 
standing behind them. Also, military forces were outside blocking three 
entrances to Rabaa Adawiya neighborhood," the protester said, adding he 
had also seen corpses with gunshot wounds at the hospital.
Yet the prosecutor 
general's office, according to a report early Sunday on state-run Nile 
TV, concluded that protesters not only initiated the clashes but also 
fired live bullets on security forces.
A police spokesman 
likewise rejected any allegations police opened fire, saying they only 
used tear gas canisters and were not responsible for the deaths.
Interior Minister Mohamed Ibrahim offered a similar view during a televised news conference.
The protesters were at fault for starting violence that wounded 14 police, none of whom fired back, he said.
"I want to emphasize here that the Interior Ministry police force has never and will never fire ts weapons at any Egyptian citizen," Ibrahim said.
Fresh clashes erupted 
early Sunday in Helwan south of Cairo between residents there and 
pro-Morsy protesters, reported state TV, citing witnesses.
Meanwhile, an attorney 
has filed a lawsuit at a district court in Cairo, asking that the 
military overthrow of Morsy be overturned. Tarek Al Kashef is basing his
 challenge on the country's constitution, specifically sections that 
stipulate that a presidential term is four years and that the president 
is the commander in chief of the armed forces. A hearing is slated for 
October 8.
 
 
