Backers and opponents of Egyptian President Mohamed Morsi have traded gunfire and thrown firecrackers at each other during brutal street fighting in Alexandria.
Riot police moved in with armored vehicles and tear gas, but not before the offices of Mr. Morsi's political party were set on fire.
Medics say a 21-year-old U.S. citizen was stabbed to death while filming the riots. It is not clear if he was working for a news agency.
Protesters are also gathering in Cairo's Tahrir Square, waving Egyptian flags and calling for Mr. Morsi's departure. They are preparing for a massive anti-government rally Sunday, the one-year anniversary of Mr. Morsi's presidency.
The marchers accuse Mr. Morsi and his Muslim Brotherhood movement of trying to undermine secular rights. Morsi supporters are also promising to fill the streets.
Egyptian military officials are urging both sides to avoid violence and negotiate. But neither side appears willing to give in.
SABER ATTA, MORSI SUPPORTER ( in Arabic ))
"Mohamed Morsi will not fall because he has a people who love him and a group who support him. It is impossible and they are wrong to think that one day Morsi will have the same fate as Hosni Mubarak."
AMR MOUSSA, OPPOSITION LEADER
"He should take the voice of the people seriously and the protests, the angry comments, as an expression - major expression - of dissatisfaction. Please take that seriously and accept the early elections."
"They don't want to recognize that there is anger and those are all people who are being pushed and directed by others. And they are missing the point, they are missing a major point in this."