Violent clashes in the Egyptian city of Alexandria have left one man dead and more than 70 people injured.
A senior security official said the male victim, a US citizen, died from a stab wound to the chest after violence erupted between supporters and opponents of President Mohamed Morsi.
General Amin Ezzeddin, a senior Alexandria security official, told the Reuters news agency that the young American was using a mobile phone camera near an office of Morsi’s Muslim Brotherhood in the city’s Sidi Gaber neighbourhood when it was being attacked by protesters.
He was rushed to a military hospital, where he died.
State news agency MENA said 70 people had been injured.
A US embassy official said: “The U.S. embassy has heard of the reports of the death of an American citizen and is seeking to confirm them.”
TV Footage showed protesters running from the scene as gunshots were heard.
The offices of the Freedom and Justice Party, the political arm of Mr Morsi’s party, were also set on fire during the confrontations.
At least four people have died since Wednesday in clashes in the Nile Delta – three in the city of Mansura and one in Zagazig – medics said.
The unrest is seen by many as a prelude to mass anti-Morsi protests planned for Sunday – marking a his first year in office.
The June 30 protest was called by Tamarod, a grassroots movement which says it has more than 15 million signatures for a petition demanding Mr Morsi’s resignation and a snap election.
It alleges that Mr Morsi reneged on his promise to be a president for all Egyptians and has failed to deliver on the uprising’s aspirations for freedom and social justice.
The president himself warned in a televised speech on Wednesday that the growing polarisation threatens to “paralyse” Egypt.
The army, which oversaw the transition from former president Mubarak’s autocratic rule but has been on the sidelines since Morsi’s election, warned it would intervene if violence erupts.
It has brought in reinforcements to key cities, security officials said.