Supporters of Egypt's ousted President Mohammed Morsi carry an injured man to a field hospital following clashes with security forces at Nasr City.
The top of this post was last updated at 9:45 p.m. ET:
About 80 people have been killed and hundreds injured in bloody clashes overnight in and around Cairo after protests escalated into violence, with supporters of ousted President Mohammed Morsi saying police shot at demonstrators.
NPR's Soraya Sarhaddi Nelson reports that Egypt's Ministry of Health has updated the number of dead to 80, with 792 injured.
In a statement, Dr. Khaled Khatib, was quoted as saying the deaths include 65 in overnight clashes in Cairo and nine others killed in the city of Alexandria.
Many of the deaths and injuries were caused by live ammunition, doctors say.
Thousands of pro-military protesters had occupied Tahrir Square, answering a call from Gen. Abdel Fattah el-Sissi to bolster his mandate after the army chief removed Morsi from office earlier this month.
The Muslim Brotherhood responded with counter-demonstrations, reports The Telegraph, prompting clashes between security forces and Morsi supporters.
Brotherhood spokesman Gehad El-Haddad said security forces began shooting shortly before pre-dawn morning prayers, AP reported.
"They are not shooting to wound, they are shooting to kill," Haddad said.
Al Jazeera is reporting that hundreds of wounded demonstrators have reported to makeshift hospitals in the area.
Update at 9:55 p.m. ET. A Sharp Divide:
"The country is dangerously divided," NPR's Leila Fadel reports from Cairo. Here's what she writes about the tension in Egypt:
"The majority seem to be against Morsi now, jubilant over his ouster. And on both sides there is a deep demonization campaign so entrenched that many Egyptians are willing to turn a blind eye to the latest deaths of largely unarmed pro-Morsi protesters. Those who do question the police behavior are quickly demonized as terrorist supporters.
" 'They are terrorists. They are human filth. They are not Egyptian,' I've heard Brotherhood detractors say.
" 'They are Christians who hate Muslims. They are unbelievers. They are the old regime. They are not Egyptian,' I've heard Morsi supporters say.
"Private liberal television channels are deepening the divide. All the Islamist channels are gone, shuttered after the military ousted Morsi. And the one's still airing are anti-Morsi. One private channel has a constant banner at the bottom of the screen, 'No to terrorists,' or, 'The people, the army and the police against terrorism.'
"State television plays patriotic songs, a soundtrack to the unrest. They play constant footage of Egypt's military. And state radio has stopped talking about the Muslim Brotherhood and started talking about 'elements' of the Brotherhood, conjuring images of criminals on the run."
Also from Egpyt, NPR's Nelson filed a report for weekends on All Things Considered about the new, dramatic turn against the Muslim Brotherhood.