Police have killed one demonstrator and arrested 54 others during protests held across Egypt against the military-backed government, the country's interior ministry says.
Three policemen were also injured during the clashes, as Egyptian security forces used tear gas to disperse the demonstrations on Friday.
Tear gas grenades have become standard use against demonstrators in several Cairo districts after protesters took to the streets against the military's ousting of former president Mohamed Morsi, Egypt's first democratically elected leader.
Security officials accused protesters of torching a police car in the canal city of Suez, and destroying another police car in the southern city of Qena.
The protests went ahead despite the country being gripped by icy winter weather, resulting in a rare snow over Cairo, and rain elsewhere.
Protesters lobbed petrol bombs at the police in the capital, the security officials said.
Such demonstrations are regarded as illegal, since they do not conform to a new law requiring organizers to give three days notice of a protest and to have it approved by the government.
In Fayoum, south of Cairo, two policemen were wounded by buckshot at a protest, sources told the AFP news agency.
Police also intervened in the Nile Delta city of Mahalla to break up clashes between pro- and anti-military protesters.
The Anti-Coup Alliance has been organizing protests demanding that the military-backed government step down ever since Morsi's government was overthrown in July.
Since Morsi's removal by the military after just a year in office, authorities installed by the army have cracked down hard on protesters.
More than 1,000 people, most of them pro-Morsi, have been killed in what Human Rights Watch called the worst violence in Egypt's modern history, and thousands of Islamists and opposition leaders have been arrested.
PHOTO CAPTION
Egyptian police fire tear at protesters.
Al-Jazeera