Clashes between loyalists of Egypt's deposed Islamist president Mohamed Morsi and other residents in Port Said on Sunday left three dead, state news agency MENA said.

Supporters of the toppled Islamist leader had opened fire during the funeral of a fellow loyalist killed in deadly Saturday violence in north Cairo, MENA reported.

The president's loyalists reportedly set several police vehicles alight during the clashes.

Those killed in the violence include a reporter from Egypt's interior ministry official website who succumbed to gunshot injuries hours later.  

Thirty others were wounded by gunfire, birdshot and bladed weapons.

Enraged local residents set ablaze several shops owned by members of the Muslim Brotherhood, according to MENA.

The Muslim Brotherhood, from which ousted president Morsi hails, denied allegations that its supporters had initiated the violence.

Street violence between rival factions has rocked Egypt since the army's overthrow of president Mohamed Morsi on 3 July amid nationwide protest against his rule.

At least 80 Morsi loyalists were killed on Saturday in clashes with police at their month-old sit-in in Cairo's Nasr City, throwing the bitterly polarised country into deeper turmoil.