Three protesters were killed and dozens wounded as Muslim Brotherhood supporters and police clashed across Egypt on Friday, the health ministry and security sources said.
Security sources said two were killed in street battles with the police in the Cairo district of Alf Maskin and a third in the capital's Abbaseya. Protesters fired weapons and hurled petrol bombs at police who responded with tear gas, they said.
The Interior Ministry said it had arrested 47 people it said were Brotherhood members during the violence, which broke out after Friday prayers.
Four policemen suffered wounds from birdshot in the port city of Suez, it said. The health ministry said 48 people were wounded nationwide.
Police cars were burned by protesters in at least two Cairo districts.
Egypt has been in a state of turmoil since the army ousted Islamist President Mohamed Morsi of the Brotherhood last July after protests against his rule.
The Brotherhood has kept up its protests against Morsi's overthrew in spite of a severe crackdown on the movement that saw the group labeled a terrorist organization in December, hundreds of its supporters killed and thousands arrested.
The Brotherhood says it remains committed to peacefully resisting what it calls a military coup against a freely elected leader.
The Brotherhood had been the most organized political force in the country in the aftermath of the 2011 uprising that toppled Hosni Mubarak, winning five elections.
Army-backed authorities face persistent street protests by Islamists and a fast-growing insurgency by Sinai-based militants that have killed hundreds of policemen and soldiers since Morsi's fall.
The government does not distinguish between the Brotherhood and the Sinai militants.
Saudi Arabia, which hailed army chief Field Marshall Abdel Fattah al-Sisi's overthrow of Morsi, designated the Brotherhood a terrorist group on Friday, a move that an Egyptian government spokesman said Cairo welcomed.
The Brotherhood said in a statement that it was "surprised" by the decision, which it said "contradicts entirely with (Saudi Arabia's) historical relations" with the Islamist movement founded in 1928.
(Reporting By Maggie Fick; Editing by Angus MacSwan)