Clashes between supporters and opponents of the ousted Egyptian President Mohamed Morsi have continued through the night, resulting in at least 30 deaths in Cairo and various other parts of the country.
Violence erupted as thousands of pro-Morsi supporters took to the streets on Friday to protest against the ouster of the country's first democratically elected president in a military coup.
The death of three Morsi supporters - reportedly killed by gunfire as they tried to march towards the military barracks where Morsi is believed to be held - triggered the ongoing mayhem.
Morsi supporters blamed the military for the incident, a claim rejected by the army.
Tens of thousands of people marched across the country in what Morsi's Muslim Brotherhood movement called a "Friday of Rage" to demonstrate against the military coup.
Rival groups also clashed in Cairo's iconic Tahrir Square. The overnight fighting finally subsided when the army separated the warring groups using armoured vehicles.
"We are not taking sides. Our mission is to secure the lives of protesters," military spokesman Colonel Ahmed Ali told AFP news agency.
Meanwhile, the US condemned the fighting and urged all sides, including the army, to stop the violence.
"We condemn the violence that has taken place today in Egypt. We call on all Egyptian leaders to condemn the use of force and to prevent further violence among their supporters," State Department spokeswoman Jen Psaki said in a statement.
"We expect the military to ensure that the rights of all Egyptians are protected, including the right to peaceful assembly, and we call on all who are protesting to do so peacefully."
A spokesman for the UN chief Ban Ki-moon quoted him calling for a peaceful end to the crisis.
"There is no place for retribution or for the exclusion of any major party or community," Ban reportedly said.
Cairo in chaos
After nightfall on Friday, a crowd of Morsi supporters surged across the 6th October Bridge over the Nile River in Cairo and clashed with opponents of the deposed president.
One man was seen apparently firing a gun, while gunshots could he heard in the area. People were seen throwing rocks as the two sides advanced and retreated in turn on the bridge near Tahrir Square.
At least two people were killed and more than 70 injured, a state TV reporter said, quoting medical personnel at a makeshift hospital in the square.
Another 17 people were killed in clashes around the country involving Morsi opponents and backers, as well as security forces, state TV reported, quoting health ministry officials.
AFP reported five policemen had been killed in the northern Sinai town of El-Arish, after a soldier was also killed in the region.
Egyptian armed forces denied reports that a state of emergency had been declared in the troubled Sinai Peninsula, and that curfews had been imposed.
Meanwhile, a deputy leader of Egypt's Muslim Brotherhood, former presidential candidate Khairat El-Shater, has been arrested, security sources, his party and state news agency MENA said on Saturday.
Security sources said Shater, a wealthy businessman seen as the movement's main political strategist, was taken into custody on suspicion of incitement to violence.
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The day's street battles began after a large crowd of Morsi supporters marched from Nasr City towards the Maspero state TV building and clashed with anti-Morsi protesters on the October 6 Bridge.
Al Jazeera's Sherine Tadros, reporting from near the bridge, said the situation was increasingly tense.
"There are thousands of people on the streets. [...] When people heard pro-Morsi people were on their way, they came towards the bridge and that's where clashes started happening. People are throwing whatever they can and it is a very intense situation."
Rioting was also reported in Al Manial district, an island in the Nile River, between Cairo and Giza, according to state TV.
'Sacrifice for Morsi'
Earlier on Friday, Mohamed Badie, the top leader of the Muslim Brotherhood, gave a defiant speech to a crowd of Morsi supporters and vowed to protect Morsi's presidency.
"We are willing to sacrifice ourselves to protect our President Mohammed Morsi," he said.
Morsi "is my president and your president and the president of all Egyptians," Badie proclaimed, thrusting his arms in the air.
"God make Morsi victorious and bring him back to the palace," he said in the speech, which was partially aired on state TV. "We are his soldiers, we defend him with our lives."
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Source: Al Jazeera