At least 40 people have been injured in clashes between anti-government protesters, Muslim Brotherhood supporters, and Egyptian police, Press TV reports.
On Friday, thousands of Egyptians held nationwide demonstrations against the government of President Mohamed Morsi, the country's first democratically elected leader.
Clashes broke out after anti-government demonstrators ransacked three Brotherhood offices in the capital Cairo, in the second-largest city of Alexandria, and in the Nile Delta city of Mahalla. According to witnesses, assailants also torched one of the buildings.
Anti-government protesters fired birdshot at Brotherhood supporters and attacked them with rocks, knives, and sticks and engaged in fist fights with them.
In response, police used tear gas and water cannon to turn back thousands of people from the Brotherhood's offices.
Police fired tear gas at stone-throwing protesters outside the Brotherhood's main headquarters in Cairo's al-Muqattam district.
Meanwhile, thousands of policemen went on strike and refused to confront the protesters in several parts of the country.
The protests against Morsi have been called by opposition parties, which also demanded snap presidential election and a new constitution.
The protesters accuse Morsi of using his power to promote the interests of the Brotherhood.
Muslim Brotherhood spokesman Yasser Mehres blamed the opposition parties for Friday's violence.
"Right now, Brotherhood buses are being burnt and there are serious injuries with people in critical condition," he said on Friday night. "It is not acceptable that Egyptians watch TV and see this farce taking place as Egyptians fight one another."
"The protesters' demands should be delivered to the government and president, not the Brotherhood office because even though the president came from the group, he makes decisions that are separate from the group," Mehres added.
The Egyptians launched the revolution against the pro-Israeli regime on January 25, 2011, which eventually brought an end to the 30-year dictatorship of Hosni Mubarak on February 11, 2011.