The death toll from the latest violent clashes in Egypt between Islamist protesters and security forces has risen to 17, a security official said Saturday.
Friday's protests were the deadliest in months, coming less than two weeks ahead of a key referendum on an amended constitution.
Raging street battles gripped Cairo and other heavily populated residential areas in several cities and provinces such as Alexandria, Ismailia, Fayoum, and Minya. Hundreds of Muslim Brotherhood members and their supporters threw fire bombs and rocks at security forces who responded with water cannons and tear gas.
Health Ministry Spokesman Mohammed Fathallah said 62 people were injured in Friday's violence.
The security official, speaking on condition of anonymity because he was not authorized to talk to the media, said police arrested 258 protesters and confiscated homemade bombs, firearms, knives, fireworks and Molotov cocktails.
Among the security forces, 17 were injured in the clashes, and three vehicles and a traffic office in Cairo's twin city of Giza were set on fire, he said.
The streets were mostly calm on Saturday and Interior Minister Mohammed Ibrahim warned that the police "will not tolerate assaults on the safety of Egypt'scitizens."
"The security apparatus will not leave Egypt hostage in the hands of the outlaws," he said during a visit to a security training headquarters.
Street protests have been a regular event across the country since the military ousted Islamist President Mohammed Morsi, who hails from the Brotherhood, in a July 3 coup after millions of anti-Islamist protesters demonstrated to demand his resignation.
Morsi's supporters have taken to the streets to demand his reinstatement and the new military-backed authorities have responded with a crackdown. Hundreds of Brotherhood members were killed when authorities broke up their protest camps, thousands have been arrested and scores were sent to trial.
Though the numbers in the streets in support of the Brotherhood dwindled dramatically amid the crackdown, Friday's protests appeared be among the most violent since a three-month state of emergency and nighttime curfew expired in November.
The government has sought to drain the group's resources, ordering last week the seizure of assets of hundreds of non-governmental groups on suspicions of links to the Brotherhood. Hundreds of the group's leaders and businessmen have also had assets seized.
The Brotherhood has called for a boycott of the Jan. 14 and Jan. 15 referendum on a new constitution drafted by a secular-leaning assembly.