Supporters and opponents of ousted Egyptian President Mohamed Morsi have been engaged in running street battles in the centre of Cairo after the pro-Morsi camp staged massive protests in the capital and other places across Egypt.
A crowd of Morsi supporters surged across the 6th October Bridge over the Nile River in Cairo after nightfall on Friday 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.
Three of the victims were Morsi supporters who were killed by gunfire as a crowd of several hundred tried to march towards the military barracks after the Friday afternoon prayer in Cairo where Morsi is believed to be held.
News agency 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 Peninsular, 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.
Military armoured vehicles raced onto the bridge late on Friday in the first major attempt to break up the clashes.
Several armoured vehicles, at least one with young Morsi opponents sitting on the roof, deployed on the bridge, aiming to chase away Morsi supporters. Military helicopters also flew toward Tahrir.
The 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 near Tahrir Square in the centre of the capital.
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."
Live TV pictures showed how hundreds of protesters clashed and cars were set ablaze, as both sides kept throwing fireworks at each other.
Riots were also reported in Al Manial district, an island in river Nile, between Cairo and Giza, according to state TV said.
A state TV reporter said that some pro-Morsi protesters in Giza decided to stop marching towards Maspero after hearing about the clashes.
'Sacrifice for Morsi'
Earlier on Friday, Mohamed Badie, the top leader of the Muslim Brotherhood, spoke of his intention not to give up on Morsi's presidency.
The dramatic appearance by Badie on stage before tens of thousands of supporters in the capital's Nasr City was his first in public since Morsi was forced from office.
In a defiant speech he said, "We are willing to sacrifice ourselves to protect our President Mohammed Morsi."
Badie also addressed the Coptic pope, Tawadros II of Alexandria, saying that he was not qualified, "to speak on behalf of the Christians of Egypt. When it comes to politics you are just a religious symbol."
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."
Badie's speech appeared to be aimed at not only firing up his supporters but also at trying to win support within the military against army chief General Abdel-Fattah el-Sissi, the defence minister who announced the president's removal on Wednesday night.